Ultimate Guide to Guitar Action
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How To Adjust Guitar Action: The Ultimate Guide!

Ever play a guitar with action that’s sky high or buzzes too much? It’s a fact, a guitar with poor action will stifle your playing and quickly rob you of enjoyment.

How do you fix it? And what tools and methods do you use to get it where it should be?

This guide explains how to make critical adjustments for most common types of guitars and the principles behind achieving great guitar action.

Editor’s Note:

This article explains, in a wholistic way, how to adjust the action on your guitar for maximum playability and enjoyment.

In order to keep the details as concise as possible, major points of adjustment are covered in broad terms first, then explained in detail further on.

What this means for you as the reader, is that you may find yourself moving from section to section in order to gain the information that fits your current situation.

I sincerely hope this guide makes sense for you and supplies the information you need to get the most out of your guitar’s action.

Steve B.

What is Guitar Action?

Guitar action refers to how the guitar feels when you play it. A guitar with good action should have the strings set at the optimal height for your instrument, match your playing style and allow you to express yourself freely.

From a physical standpoint, the word “action” also fits the context of how you manipulate the guitar. As you play, your fret hand is literally where most of the action is.

Adjusting the action on a guitar refers to changing the distance between the strings and the fretboard. Moreover, it can be a delicate process as it requires precise measurements and careful handling of the instrument.

Telecaster divider

Why Action Matters

If your guitar’s action is poor, it’s not only annoying, it’s distracting. In other words you’re not getting the most out of your playing time or enjoying the experience as much as you could.

In my experience, well over 90% of guitars suffer from high action. For new guitarists this can be a deal breaker – the struggle is very real. Plus they usually don’t know what good action is supposed to feel like.

Conversely, if the action is too low, the strings may buzz against the frets when played, resulting in poor sound quality.

If your guitar doesn’t play the way you’d like, what follows is the remedy to curing your poor action woes.

The Tools You’ll Need

The tools required to adjust virtually any guitar’s action are really quite modest and certainly won’t break the bank. A few of the most common tools you’ll need include:

  • An appropriate truss rod adjuster for your specific guitar
  • Screwdrivers and allen keys to make bridge saddle adjustments
  • A fine measuring tool to determine string height
  • Feeler gauges or similar reference tools
  • And ideally, a set of radius gauges
Feeler Gauge
Feeler Gauges
String Height Tool
A String Height Tool
Radius Gauge
Radius Gauges

Depending on your instrument you may need additional things like files or sandpaper for trimming things like acoustic saddles.

For a complete list of the essential tools for setting guitar action and further setup adjustments, check out our Guitar Setup Tools Guide.

How to Measure Guitar Action

Start With an Assessment

Assessing the current state of your guitar’s action is your starting point. Sometimes you can easily see with the naked eye that the strings are too high or low to begin with.

Look at where the body meets the neck, do the strings seem excessively high? Or are they too close to the frets?

String Height is Way Too High
String Height is Way Too High

Now sight down the edge of the neck from just behind the nut looking towards the bridge. Do the strings seem to rise too quickly? Or are they nearly touching the tops of the frets.

Strings that are too high will seem hard to play. Strings that are too close will tend to buzz or even fret out in the upper register when you bend them.

Make some mental notes about what you observe.

As for neck relief, the neck may also look like it has a bit too much “bow”. Too much relief will make the strings in the middle of the neck feel particularly spongey or little too hard to manipulate.

Guitar Neck with Too Much Relief
Guitar Neck with Too Much Relief

The neck may also look pretty straight or even have a bit of an up-bow or a slightly rounded (humped) curvature. If this is the case, once again you’ll find the strings a little buzzy.

Commit what you’re feeling to memory. It’ll come in handy as we work through the process of adjusting the truss rod and setting the action properly.

Refer to Factory Specifications

Here’s a generalized chart of factory setup specs for common brand-name guitars.

Keep in mind these measurements are not absolute and subject to many different variations such as playing style, string gauge, condition of the instrument etc.

All string heights measured in inches at the 12th fret:

Gibson Les Paul6th string: 1/16″ – 5/64″1st string: 3/64″ – 1/16″
Fender Vintage6th string: 1/16″ – 5/64″1st string: 1/16″ – 5/64″
Fender Modern6th string: 1/16″ – 5/64″1st string: 1/16″ – 5/64″
Martin Acoustic6th string: 3/32″ – 7/64″1st string: 1/16″ – 5/64″
Classical6th string: 7/64″ – 1/8″1st string: 3/32″ – 7/64″
Fender Bass4th string: 3/32″ – 1/8″1st string: 5/64″ – 3/32″

How to Measure String Height

Measure String Height at the Nut

String height at the nut is measured by assessing the air gap at the first fret. This can be done using feeler gauges, or by eye if you have enough experience.

To use feeler gauges, pick a gauge that seems appropriate and measure the air space between the top of the fret and the underside of the string.

String Height at the 1st Fret
String Height at the 1st Fret

Keep in mind that neck relief and bridge height will influence this measurement. Therefor it is essential these factors be within a reasonable range before you commit to cutting any string slots at the nut.

The following measurements can be used a general guide for most guitars to at least get you in the ballpark. You can then tweak them to your own personal preference. Keep in mind that once a string slot is cut, it’s cut.

All string heights measured in inches from the bottom of the string to the top of the 1st fret:

1st String.014″
2nd String.017″
3rd String.019″
4th String.019″
5th String.022″
6th String.024″

Measure String Height at the 12th Fret

Using your preferred fine measuring tool, here’s how to measure your string height:

  1. Hold the guitar in the playing position.
  2. Starting with the low E string, measure the distance from the bottom of the string to the top of the 12th fret. (Coins work really well as a quick reference).
  3. Record the measurement.
  4. Next, move to the high E string and repeat the same measurement technique.
  5. Record the measurement.
Measuring first string height at the 12th fret
Measuring the first string height at the 12th fret.
Measuring sixth string height at the 12th fret
Measuring the sixth string height at the 12th fret.

Note: The 12th fret this is a common reference point as it’s the middle of the string between the nut and the bridge.

If you want more precision, use the 8th and 14th frets. This technique will also allow you to account for effects of relief.

Don’t worry about measuring all the strings in between, setting the outer strings will give us a guideline for the remaining strings.

Lastly, move to the end of the neck at the first fret. Does it take a bit too much pressure to push the strings down? Or do they buzz when you play them open?

In either case, it means we’ll have to make one or more adjustments to get the strings to ring out properly and feel right at the same time.

How to Measure Fretboard Radius

Radius gauges are an indispensable tool for coaxing the maximum playing potential out of a guitar. By matching the radius of the fretboard with the radius of the strings at the bridge, it’s possible to achieve superior guitar playability.

Radius Gauge
Measuring a fretboard radius using a continuous curve gauge.

Chances are your fretboard radius is fairly common if your guitar is manufactured by a popular brand. Here’s a table listing some of the most typical radii used by larger manufacturers:

Common Fretboard Radius Measurements

Vintage Fender guitars7.25″
Most modern Fender guitars9.5″
Many PRS, Squier and off-shore Fender type models10″
Most Gibson, Epiphone, Ibanez and Gretsch guitars12″
Most Taylor guitars15″
Most Martin, Takamine and Jackson guitars16″

Of course, if you’re unsure or have a more unique model, it’s a pretty quick process to find the factory specs for your particular instrument’s fretboard radius through the manufacturer’s website. Or you can refer to this excellent list of radius measurements organized by manufacturer here.

In practice, ALWAYS measure the fretboard radius of service instruments to verify you have correct information.

Radius gauges come in a variety of styles and price points. In general, they all do the same job and won’t break the bank.

Here’s a recommended complete set of radius gauges with some excellent extras:

15 Pieces Guitar Luthier Tools Set Including Guitar Radius Gauge, String Action Ruler Gauge, 32 Blades Feeler Gauge, Guitar Notched Radius Gauges for Guitar and Bass Setup

A complete set of radius gauges and fine measuring tools.
Check availability here >>

To measure fretboard radius, follow these steps:

  1. Pick a notched radius gauge you think is the right one.
  2. Make sure it matches the wider spans of fretboard close to or at the body joint (14th – 18th frets) without any gaps.
  3. If it doesn’t match, move to the next size up or down and repeat step 2.
Confirming a Gibson Les Paul 12 Inch Fretboard Radius
Measuring a Gibson Les Paul fretboard radius with a notched gauge.

To measure string radius at the bridge, follow these steps:

  1. Pick a solid curve radius gauge that matches the fretboard.
  2. At roughly 1/2″ ahead of the saddle(s), rest the gauge against the strings with as little pressure as possible.
  3. Check that all strings contact the gauge by gently picking each string in turn. Each string should buzz slightly if it is contacting the radius gauge.
Measuring Radius at the Bridge
Measuring Radius at the Bridge

If any strings do not touch the gauge you’ll have to adjust the saddle(s) to match. Because different instruments require different approaches to making these adjustments, I’ll cover them individually in the section on How to Adjust the Action on Different Types of Guitars.

How to Measure Neck Relief

There are a number of ways to measure or “read” neck relief. My preferred method involves measuring the gap under the 3rd string around the 7th to 9th frets.

Measure neck relief in the 7th to 9th fret area
Measure neck relief in the 7th to 9th fret area.

If there isn’t a gap it means the neck is too straight or may have a back bow. We’ll address this later in the article in the section: “How to Adjust the Truss Rod“.

Here’s how to quickly and accurately measure neck relief:

  1. While holding the guitar in a playing position, press the G string down at the 2nd fret with your fret hand, and at the same time, the 14th or 15th fret with your pick hand.
  2. Now look at the G string at the mid-point of this span – around the 7th to 9th frets.
  3. Look for a gap of light between the top of the frets and the underside of the string itself. The gap should be somewhere between .006″ and .018″ or .15 mm and .46 mm respectively depending on the instrument.

For quick reference, the gap should look about the same thickness as the diameter of the 1st or 2nd plain strings.

If the gap is more than described, or not there at all, we’ll have to adjust the truss rod.

These initial measurements will give you an excellent idea of where your guitar’s action currently sits. Depending on how you want the guitar to feel as you play, you can increase or decrease these readings to match your style.

Now that you have your reference points, you can begin the most important process of setting your guitar’s action: balancing string height with truss rod relief.

How to Adjust the Truss Rod

Neck relief should be set so that it’s not too straight – which can cause excessive buzzing, or have too much air under the strings – which causes the neck to feel spongey and harder to play.

Depending on the manufacturer, there are basically four different types of truss rod adjusters:

Regardless of the type of truss rod adjuster or which end of the neck it’s located at, they all work the same way:

  • Tightening the adjuster increases pressure which straightens the neck. This brings the frets and the strings closer together.
Guitar Action - Truss rod effect of tightening
The effect of tightening a truss rod
  • Loosening the adjuster decreases pressure which adds relief. This adds air between the frets and the strings.
Guitar Action - Truss rod effect of loosening
The effect of loosening a truss rod

To set the relief that’s perfect for your how you like your action, make small incremental bridge height and truss rod adjustments until you’re satisfied with the results.

How to Adjust Guitar Action: An Overview

By now you should have a good idea of the target measurements you’re aiming for, the tools you need and how to make the adjustments to get you there.

To adjust the action on a guitar, there are three main points you need to focus on:

  • The nut
  • Neck relief
  • The bridge

By raising or lowering each element, you can find the perfect balance of playability for both the instrument and the player.

Guitar action adjustment points
Guitar action adjustment points

Make Preliminary Adjustments

Making preliminary adjustments gets the instrument in the ballpark and helps us better determine what the final adjustments should be. It also helps us control problems that can pop up if we commit to a setting prematurely.

For example, if we cut the nut slots to an optimal depth then straighten the neck, the nut slots will be too low causing the strings to buzz. The only remedy then is to repair or replace the nut.

To use an analogy, let’s write a rough draft before we commit to the final copy.

Additionally, try to make preliminary adjustments using the old strings if at all possible – especially if the guitar hasn’t been adjusted for a while.

Why? Because new strings will quickly get trashed from repetitive tensioning during the adjustment process. Save the fresh strings for the last few steps to maintain their full integrity.

To begin setting the guitar’s action, follow this series of preliminary adjustments:

  1. If possible, lower or raise the bridge or saddle(s) to get them in the ballpark. It’s ok to be conservative, we want to “creep” the individual adjustments gradually towards the ultimate goal.
  2. Read the neck relief and make a quick adjustment if necessary.
  3. Make sure the nut is cut properly. If it seems ok, leave it alone. If it has issues and needs to be re-cut, check out the quick tutorial on re-cutting a nut here. If it needs to be repaired, check out this article on nut repair.

Next, we’ll look at the fine adjustments we need to coax the most playability out of your guitar.

How to Adjust the Action on Different Types of Guitars

Different types of guitars, electric and acoustic for example, have different types of action adjustments. Nonetheless, they all follow the same basic principle of getting the string height and neck relief to work together.

I must stress that, as we go from instrument to instrument, we’re going to assume the nut is in good shape.

Why? Because regardless of the type of guitar, the nut is a fixed point and shouldn’t need further adjustment once it’s set. For help on setting the nut height, refer to the links in the Preliminary Adjustments section.

Otherwise, the truss rod and bridge are the areas that really need the attention – the vast majority of your work will involve setting the bridge or saddle height and adjusting neck relief.

Author’s Note: Getting the greatest possible action out of a guitar relies heavily on all critical adjustment points being within acceptable limits. If you’re in doubt or think these adjustments are beyond your comfort level, take your guitar to a qualified tech.

Steve B.
Acoustic Guitar Divider

Steel String Acoustic Guitars

Whether you like your action a little higher or as low as possible, great action on an acoustic guitar, like any other guitar, involves finding the perfect balance between the nut height, neck relief and saddle height.

Most acoustic guitars come with a one-piece saddle made of natural or man-made materials. The most common being bone, plastic or graphite.

Martin Compensated White Tusq saddle
Measuring the radius of a Martin compensated Tusq graphite saddle.

As mentioned previously, you should have the neck relief at least in the ballpark to minimize re-adjustments.

In my experience, acoustic action is usually set too high – either from the factory or due to the stresses of aging. Achieving comfortable low action on an acoustic involves trimming an appropriate amount of material from the bottom of the saddle – not the top, to bring the string height down.

Saddle marked for trimming
Bottom of the saddle marked for trimming.

During the trimming process, it’s not uncommon to have to reinstall the saddle and strings a couple of times to check the action. This is where keeping the old strings on really comes in handy

How to Adjust the Action on an Acoustic Guitar

To adjust the action on your acoustic follow these steps:

  1. Measure neck relief and adjust to within your own acceptable limits.
  2. Make sure individual nut slot heights are set properly. Adjust if necessary.
  3. Remove the strings.
  4. Carefully remove the saddle.
  5. Check that the saddle slot is clean and make sure there are no pre-existing shims.
    • If the strings are already too low and you do need to install a shim, use a piece of stiff material with a thickness of roughly .025″ (0.635 mm) cut to the appropriate length and width. An old credit card works perfectly for this.
    • Once you’ve installed the shim, skip to step 8.
    • If you are removing saddle material, continue to step 6.
  6. Mark a straight line along the bottom edge of the saddle, roughly .025″ from the bottom is a good start. Note: a little goes a long way. In other words, removing a small amount of material can make a big difference in how the action feels. Plus it’s better to creep towards your target rather than overshooting it.
  7. Remove the excess material from the bottom using a sander, file or sandpaper. Aim to “split the line” and at the same time, make sure the bottom of the saddle is perfectly flat.
  8. Reinstall the saddle and strings.
  9. Tune to pitch.
  10. Check neck relief again. Adjust if necessary.
  11. Check for playability. Pick a few single notes and strum a few chords up and down the neck in multiple places. The action should feel comfortable and the notes should ring true without the strings buzzing.
  12. If necessary, repeat steps 3 through 11.
  13. Install new strings and tune to pitch.
  14. Check neck relief and playability. Adjust if necessary.
  15. Fully stretch the new strings and re-tune to pitch.
  16. Play and enjoy!

You’ll notice there’s a lot of reference to checking neck relief. Why? As you remove and reinstall the strings you’re also removing and reapplying pressure. This can cause neck relief to change as compression is redistributed.

Using coins to check string height on a Martin LX1 acoustic
Using coins to check string height on a Martin LX1 acoustic

You’ll also notice new strings have slightly less tension and are more elastic. This will cause the neck to relax a little. Therefor keeping a constant close eye on neck relief is an important part of the process.

Note: Sometimes the an acoustic’s saddle radius doesn’t match the fretboard radius. whether you decide to adjust it or not requires careful consideration.

On some guitars this mismatch is intentional, the saddle radius will read flatter compared to the fretboard. A common trait with Martin guitars, this is due to either the use of a compound radius (a gradual flattening of the radius along the neck) or extra height added to the bass side to allow room for thicker string vibration.

Conversely, you may find the saddle has an overly rounded radius. This is usually due to overly-standardized production that has neglected the finer points, preferring quantity over quality.

Lastly, all the steps regarding action described above are exactly the same for a twelve string acoustic – the only difference is in the number of strings you get to deal with!

Les Paul vs Stratocaster divider

How to Adjust the Action on an Electric Guitar

For the most part, adjusting the action on an electric guitar follows the same procedures as previously mentioned – but with one significant exception: electric guitars are inherently designed to be more adjustable in order to fine tune string height, radius and intonation length.

Though the goal of adjusting the action at the bridge is the same, the type of bridge your electric guitar has will greatly affect the types of tools and processes you use.

For example, adjusting the bridge on a typical Fender-made product will be very different from adjusting the bridge on a Gibson Les Paul.

Additionally, make sure you keep a close eye on string tension. Making these adjustments will definitely affect string pressure and potentially cause misreads. To maintain accuracy, good practice is to continually check the condition of your strings and keep them as close as possible to normal tension.

That said, let’s have a look at how to adjust the action on some of the most common types of electric guitars:

Fender Style Electric Guitars

Strat Guitar Divider

Stratocaster guitar bridges come in two basic forms according to the type of bridge mounting screws: the classic six-point and the modern two-point systems.

Overall bridge height can be adjusted by means of the bridge mounting screws:

Modern Fender Stratocaster 2-point bridge
Modern Fender Stratocaster 2-point bridge.

Though each type of tailpiece is originally designed to be floating, it can also be “hard-tailed” or set flat to the body.

If the bridge is set to be hard-tailed, the process of setting your action is fairly straight forward.

If the tailpiece (ie: the bridge) is set to be floating, adjusting the amount of rise off the body surface will affect the overall height of the strings.

Therefor, when adjusting the claw-plate springs in the back, be sure to re-check your string height – more spring tension brings the strings closer to the fretboard and vice versa.

Adjusting claw plate screws in the spring cavity of a Stratocaster
Adjusting claw plate screws in the spring cavity of a Stratocaster.

Stratocaster bridge systems feature individual saddles that are fully adjustable in three aspects: height, radius and intonation length.

Stratocaster bridge radius
Stratocaster bridge radius.
Stratocaster saddle height adjustment screws
Stratocaster saddle height adjustment screws.

Each saddle has two forward-mounted grub screws that can be used to set the string height, and at the same time, match the radius. The screw at the rear of the bridge plate is used to set intonation length.

Adjusting saddle height on a Stratocaster
Adjusting saddle height on a Stratocaster.

Typical US (Imperial spec.) models use a 1/16″ allen key for the grub screws, whereas import and many MIM units use a 1.5 mm allen key driver.

How to Adjust Action on a Stratocaster Bridge:

First and foremost, we’re going to assume you have a fresh set of strings on, the nut and neck relief have been adjusted, and you are ready to go!

  1. Adjust the bridge mounting screws:
    • Relax string pressure until the back of the bridge plate contacts the body surface.
    • If necessary, adjust all bridge mounting screws to make sure the bridge plate is reasonably flush with the body.
    • Starting with the outermost screws, adjust the bridge mounting screws until the back of the bridge plate just begins to rise off the body surface.
    • Back off each bridge mounting screw equally an additional 1/4 to 1/2 turn.
  2. Tune the strings up to pitch.
    • If floating, adjust the claw plate spring pressure until the back edge of the bridge measures 1/8″ or 3.18 mm off the body surface at pitch. Note: This height can be adjusted to better match your playing preference.
    • If hard-tailing, continue to step 5.
  3. Check neck relief. Adjust if necessary.
  4. Adjust the 1st string saddle height to its lowest acceptable limit. Note: individual string heights are set by adjusting the two grub screws at the front of each saddle
  5. Adjust the 6th string saddle height to its lowest acceptable limit.
  6. Using the appropriate radius gauge, set the remaining string heights to match.
  7. Stretch the strings out fully and retune to pitch.
  8. Double check for ease of action and playability.
  9. Enjoy!

Author’s note: When setting up a Strat to be floating, the bottoms of the saddle plates should ideally be level and in line with the trajectory of the strings when at rest.

Stratocaster bridge with slight lift
A slightly lifted Stratocaster bridge showing saddle plates in line with the string trajectory.
Tele Guitar Divider

The beauty of a Telecaster lies in its simplicity. Originally designed to be a working musician’s guitar, the focus was on the balance of utility and performance.

For the most part, achieving great action on a Telecaster is the same as previously mentioned instruments. But once again, the main difference lies in how you deal with the bridge components – namely the saddles.

Adjusting a Telecaster bridge with modern individual saddles is essentially the same process as on a Stratocaster – but without the need to adjust any bridge mounting screws.

Modern Telecaster saddle bridge detail
Modern Telecaster bridge detail.

Adjusting a vintage style Telecaster bridge with three barrels is slightly different in a couple of aspects. For one, you may need a fine slot screwdriver to adjust the grub screws.

Secondly, it’s important to understand that adjusting one side of the barrel influences the other side slightly. Therefor it’s important to constantly re-check the overall height and radius measurements you’re aiming for.

Vintage style Telecaster saddle height adjustment
Vintage style Telecaster saddle height adjustment.

How to Adjust Action on a Telecaster Bridge:

Let’s assume (again) you have a brand new set of strings on, the nut and neck relief have been checked and adjusted to your satisfaction, and you’re ready to go!

  1. Tune the strings up to pitch.
  2. Check neck relief. Adjust if necessary.
  3. Adjust the 1st string saddle height to its lowest acceptable limit.
    • Note: Whether the saddles are individual to the string or the two-string barrel type, string height is set by adjusting the two grub screws at the front of each saddle.
  4. Adjust the 6th string saddle height to its lowest acceptable limit.
  5. Using the appropriate radius gauge, set the remaining string heights to match.
  6. Stretch the strings out fully and retune to pitch.
  7. Double check for ease of action and playability.
  8. Enjoy!
Les Paul Divider

Gibson Style Electric Guitars

Adjusting the action on Gibson style electric guitars once again follows the same basic process as any other: we want to start by making sure the nut height and neck relief are set according to your preferences using the methods described above.

Next, assuming you have a new set of string on to work with and the appropriate tools, let’s have a look at how to make action adjustments at the bridge.

Gibson type bridge adjustment points:

Gibson Tune-O-Matic bridge height adjustment thumbwheels

How to Adjust Action on a Gibson Style Bridge:

  1. Make sure the strings are tuned to pitch.
  2. Double check neck relief. Adjust if necessary.
  3. Using the appropriate tool, adjust the treble side of the bridge to its lowest acceptable limit.
  4. Check string tension making sure it’s at least close to being in tune.
  5. Adjust the bass side of the bridge to its lowest acceptable limit.
  6. Once again check string tension.
  7. Double check string height and readjust the bridge if necessary.
  8. Stretch the strings out fully and retune to pitch.
  9. Double check the action throughout the neck is to your liking.
  10. Play away!

You may have noticed I haven’t mentioned anything about using a radius gauge. This is for good reason.

Tune-o-matic bridge radius
Tune-o-matic bridge radius

The interesting thing about Gibson tune-o-matic type ABR and Nashville bridge design is in the fact that the bridge unit itself acts as a unified carriage – the individual saddles are not height adjustable themselves.

Because Gibson type saddles are not height adjustable, setting the radius may require cutting the saddle slots. This process is not to be taken lightly as there are significant consequences.

Why? Well for one, older bridges, particularly those found on older and vintage instruments, suffer from what’s called a “collapsed bridge” or “bridge sag”. This is a condition where the bridge loses its original radius over time due to continuous pressure from the strings.

Collapsed bridge
A collapsed bridge on a 1977 Gibson RD Artist. Note the top of the bridge is curved when it should be straight.

And two, if you cut one saddle slot too low, you have to adjust the others to match. In other words, you must be precise in your measurements and careful in execution – once it’s cut, you cannot undo it.

In this respect, Fender type bridge design has a significant advantage in the ability to fine tune without alteration.

Either way, recutting the saddle slots is a destructive process requiring careful consideration, especially when dealing with an older bridge that’s already compromised.

If you do decide to refine the radius by cutting the saddle slot depths, you can use the same tools used for cutting the nut slots.

Grizzly T25458 Nut Files, Set of 8

Nut slotting files can be used to recut saddle slots and refine the string radius.
Check availability here >>

Additionally, you should do this BEFORE you set your string heights. If you try to do it afterwards, you’ll have to re-set your outer string heights all over again.

Should I Top Wrap or Not?

What does top wrapping a stop tailpiece have to do with action? Well, the answer lies in why it’s adjustable in the first place.

According to original Gibson advertising literature, there was an intentional benefit baked into the design to begin with: the, “Tailpiece can be moved up or down to adjust tension”.

Gibson 1960 Catalogue Page 10

To this day, there is a hot debate as to whether the strings should be oriented one way or the other. One side claims, “If it’s good enough for (insert guitar hero name here), it’s good enough for me.” versus “If it was designed that way, then that’s the way it should be done.”.

It really comes down to a matter of preference. If you do happen to favor one or the other, which side are you on? By all means, feel free to leave a comment in the comments section below.

Ibanez Guitar Divider

Guitars with Locking Systems

As a group, guitars with locking systems are purpose-built for fast action. When build quality and material components are good, these guitars perform like thoroughbreds being nearly effortless to play.

Due to the nature of the locking system, these guitars also fall into a category all their own. Along with other features, the locking system also affects the process of setting the guitar’s action.

Many players find the process of working on a locking system incredibly frustrating. For good reason: you’re dealing with a host of mechanical points that have to be locked or unlocked while at the same time work with loaded springs under tension.

In reality, the process of adjusting the action on a guitar with a locking system is really not that complicated. You just need the appropriate tools, and follow a logical method to get the guitar’s action where you want it to be.

The Most Common Issue – The Bridge is Too High or Low

One of the most common pain points associated with locking systems is the change in bridge height when you switch string gauges. The bridge will get “decked” – that is, pulled back into the body with lighter strings, or rise sky high when going to a heavier gauge.

To correct a locking bridge height that is too high or low, refer to steps 4 thru 7 below.

Common Locking Bridge Adjustment Points

Adjusting the bridge to level is done by adjusting the claw plate screws located in the spring cavity.

EVH Wolfgang spring cavity showing claw plate adjustment screws
EVH Wolfgang spring cavity showing claw plate adjustment screws

When the spring pressure is equalized with the string pressure, the bridge plate should be relatively flush with the plane of the body.

Locking system bridge properly levelled
Locking system bridge properly levelled.

Similar to Gibson style and modern Fender Strats, locking system bridges use a two-point adjustment system to raise or lower the entire bridge unit.

Locking tremolo bridge height adjustment points
Locking tremolo bridge height adjustment points
Locking Nut Shims

Shims of different thicknesses can be used to adjust the height of the locking nut.

Locking nut shim placement
Locking nut shim placement.
Locking nut and various shims
Typical Floyd Rose locking nut and various shims.
Locking Bridge Saddle Shims
Allparts BP-2214-001 Bridge Shim Set

Saddle shims can be used to adjust the height of individual saddles to match the fretboard radius.
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How to Adjust the Action on a Guitar with a Locking System:

For the sake of popularity, we’re going to use a standard Floyd Rose type locking system for reference.

  1. Make sure the bridge is in as level a position as possible. See step 4 below for instructions on how to do this.
  2. With the strings at tension, carefully asses neck relief is within tolerance. Adjust if necessary.
  3. Check string height at the nut.
    • How to adjust a locking nut if it needs to be raised or lowered:
      • Remove the pressure pad bolts, pads and any nut mounting screws. Note: string tension will keep the nut in place.
      • Place a suitable block such as a tongue depressor under the back of the locking bridge. This will stop it from collapsing into the body.
      • Starting with the first string tuner, carefully back off each string 2 or 3 turns to reduce overall string tension.
      • To further reduce spring load on the guitar, carefully remove 1 spring from the cavity in the back of the body.
        Spring load should now be reduced enough so that you can either add or remove shims from underneath the locking nut.
      • Insert one of the 3mm locking pad machine screws 2 or 3 turns into the center position on top of the nut. Using the screw as a handle, you should now be able to gently pull the nut up vertically to add or remove shim material underneath. If the nut seems to still have too much pressure on it, back off the tuners a bit more and / or remove another spring if necessary.
      • Add or remove shims underneath as required. Note: If, after removing all shims, the locking nut needs to go still lower, the nut seat will have to be re-milled. If this is the case, take it to a pro as this is a highly specialized process and beyond the scope of this guide.
      • Using a stepped approach, carefully bring the strings back up to tension and reinstall any tremolo springs previously removed.
    • Recheck that the nut is at an acceptable height. If necessary, readjust using the method previously described.
    • Recheck that the neck relief and bridge are also within acceptable limits. Readjust if necessary.
    • Reinstall the nut mounting screws. Note: It is not necessary to reinstall the pressure pads just yet.
  4. With the strings at tension, check that the bridge plate is level with the plane of the body. Alternatively, the bridge plate can be lined up with the trajectory of the strings.
    • How to level the bridge:
      • If the back end of the bridge plate is too high, tighten both claw-plate screws equally 1/2 to 1 full turn each.
      • If the back end of the bridge plate is too low, loosen both claw-plate screws equally 1/2 to 1 full turn each.
      • Retune the strings to pitch.
      • Check that the bridge plate is level. If not, repeat the above steps according to the condition of the bridge until it is level.
    • Double check the strings are at pitch.
  5. Adjust the treble side fulcrum stud up or down until the 1st string height is set to its lowest acceptable limit.
  6. Adjust the bass side fulcrum stud up or down until the 6th string height is set to its lowest acceptable limit.
  7. Recheck that the bridge is level and that the nut height and neck relief are still within acceptable limits. Make refining adjustments if necessary.
  8. Using the appropriate radius gauge, check that the radius of the strings indeed matches the radius of the fretboard.
    Important Note: Whether the saddle radius matches the fretboard radius or not is highly dependant on the quality of manufacture. In my experience, locking system saddles rarely match the fretboard radius and require shims to get a perfect match.
    • How to adjust string radius on a locking system bridge:
      • Remove tension from the string you want to adjust.
      • Record the intonation point for future reference.
      • Loosen and remove the saddle lock down screw attached to the saddle you’re adjusting.
      • Carefully lift up the saddle to expose a gap under the front portion. Pulling the string up vertically usually works well for this.
      • Insert the appropriate size shim under the saddle. This can be anything between .005″ to .015″ or .127 mm to .381 mm depending on the amount of radius gap you need to compensate for.
      • Realign the saddle to its original intonation point.
      • Reinstall and tighten the saddle lock down screw.
      • Tune the string up to pitch.
      • Check that the string height now matches the radius. Readjust if necessary.
    • Check that all strings are at pitch.
  9. Recheck that the nut height, neck relief and condition of the bridge are set to your liking.
  10. Line up and level the fine tuner adjustment screws making sure there’s enough room for adjustment after lock down.
  11. Double check that the saddle lock down screws are secure.
  12. Reinstall the nut pressure pads and pad bolts, and lock them down.
  13. Recheck that the guitar is tuned to pitch. Fine tune if necessary.
  14. Play!

For most systems, the above method works very well. But variations between manufacturers will require adapting some principles to make things work for the particular unit.

Floyd Rose vs Kahler Systems

For example, adjusting the locking nut for a Kahler system works exactly the same as described above, but adjusting the bridge is a very different animal – more like that of a Strat but on steroids. Plus there’s no true locking mechanism for the strings.

Kahler floating bridge
Kahler floating bridge
Jazz Guitar Divider

Adjusting Action on Archtop, Jazz and Semi-Acoustic Guitars

Setting the action on archtop, jazz and semi-acoustic instruments is very similar to that of acoustic guitars – with some interesting exceptions.

Many traditional archtop jazz guitars come fitted with a pre-intonated, height adjustable bridge system. The saddle component is a typically a single piece of hardwood or metal set atop of a base plate fitted with adjustable thumbwheels.

Jazz Guitar Compensated Bridge
Archtop guitar compensated bridge height adjustment thumbwheels

With these instruments, adjusting string height for better action is a simple matter of raising or lowering the saddle using the thumbwheels.

Interestingly enough, even a straight metal bar, as used in Gretsch’s 7576 Country Club, can be remarkably effective and musical when adjusting the action on a jazz-box.

Putting a wedge in the door of the future, more “modernized” instruments make use of tune-o-matic type bridges and are thus, fairly straight forward.

Setting the action on these guitars is essentially the same as with Gibson type instruments.

Vintage Kay model K6550 Pacer jazz guitar with a replacement tune-o-matic style bridge
Vintage Kay model K6550 Pacer jazz guitar with a replacement tune-o-matic style bridge.
Classical Guitar divider

Adjusting Action on a Classical Guitar

For the most part, adjusting the action on a classical guitar follows the same process as steel string acoustics, but with a few very important differences:

  • Classical guitars traditionally have a flat fretboard, therefor there’s no need for measuring or adjusting a radius.
  • Due to lower string pressure, many classical guitars are not equipped with a truss rod – no adjustment is necessary.
  • Action on a classical guitar will be a little higher due to the higher elasticity and tendency of the strings to vibrate more aggressively. This means both the nut and the saddle must be set fractionally higher.
  • If you have to remove the saddle to make adjustments more than once, it’s not very practical to un-weave the strings at the bridge. Instead, loosen the string tension and carefully insert a suitably sized wedge just ahead of the saddle. This should allow you enough lea-way to remove the saddle, make an adjustment and reinstall it.
Removing a classical saddle bridge
Removing a classical saddle bridge
Bass Guitar divider

Adjusting the Action on a Bass Guitar

Adjusting the action on a bass guitar typically follows the same process as electric guitars. Most of the “action” is set using the bridge components.

Depending on the architecture, the adjustment points and methods are essentially the same, just on a larger scale (no pun intended). For example, larger strings means a little more string height is needed along with a touch more neck relief.

Measuring string height on a Peavey T-20 bass
Measuring string height using coins on a Peavey T-20 bass

From a player’s point of view, one major consideration is in whether you use a pick, fingers or combination of both. These various techniques have a substantial influence on how the action is set which is heavily dictated by the player’s style.

Should Action Be High or Low?

Whether you like your guitar’s action high or low depends on a number of factors:

  • The type of instrument you play
  • Your technique or approach to playing
  • Your tolerance for string buzz
  • Your general taste in music
  • Your level of experience – or even age

Considering the range of musical styles and instruments, these factors suggest an incredibly wide range of variations in how action should be set.

How to Set the Lowest Action on a Guitar

Before setting the lowest action your guitar will allow, make sure you have covered the preliminary adjustments and general action adjustments for your specific type of guitar listed above.

Next, you’re going to check the neck in multiple areas. Checking these multiple points magnifies your sense of how the guitar sits. It also lets you determine the limits of your guitar’s action and helps balance it with your playing style.

Here are the specific steps to measure for the lowest action your guitar will allow:

  1. Hold the guitar in the playing position.
  2. While looking at the Low E string around the 12th to 15th fret area, make a mental note of or take physical distance between the tops of the frets and the underside of the string.
  3. On the same low E string, play a few notes up and down the neck in between the 10th and 17th frets. if there’s too much resistance, the strings are too high. If the string buzzes, the string height is already set too low, or one or more frets need attention (which is common where the neck meets the body).
  4. Again on the same low E string, move to the third fret area and play a few notes up and down the neck to make sure it doesn’t buzz or feel too spongey. If it does, most likely the neck still needs a truss rod adjustment (or less likely, you may need some fret work).
  5. Now move to the high E string. Again, make a mental note of (or measure) the string height above the frets around the 12th to 15th fret area.
  6. In that same area, play a few single notes up and down the neck. There should be no buzzing and very little resistance under your fingers. Each note should ring true and clear.
  7. Now do at least a full tone bend (more is better) on every fret from the 10th to 17th frets. If you find the string buzzing or fretting out, the action is already set too low or one or more frets need attention.
  8. Lastly, using a similar method as the described for the low E, move to the 3rd to 5th fret area on the high E string. Play a few notes in that section and check for any buzzes, sizzles or excess “air” under the string. If there are issues, once again it suggests the truss rod needs adjustment, or a fret or two may need attention.

The best and lowest action you can achieve will be a direct result of following this process. Moreover, this same process can also be used for the vast majority of guitars.

Super low action on a Telecaster
Measuring super low action on a Telecaster

You’ll notice nothing is mentioned about the inner strings: 2nd, 3rd, 4th and 5th. This is because we’re using the outer strings to determine our lower limits. The remaining strings will fall in line as we make fine adjustments later on.

There are a few other subtle hot spots that will manifest depending on the strings and instrument, but the fret areas mentioned above are those that tend to be extremely consistent.

The reality is, whether you prefer your action high or low or are still trying to figure it out, the best guitar action sticks to a straight forward principle: it should feel right.

The Pros and Cons of High Action vs Low Action

Contrary to most opinions, high action is not necessarily bad. Higher action will allow an instrument to “speak” a little better; it produces more volume, but you have to work for it.

One of my local clients, Ian Crichton of the prog rock group Saga, likes his action a little higher. He wants to hear the notes ring loud and true with a good amount of “ping”. His comment about high action was, “You get used to it.”.

Conversely, a guitar with low action requires less energy to manipulate the strings.

For instance, many metal players prefer their action very low in order to accommodate lightning fast shredding techniques such as sweeps, arpeggios, pivots etc.

Compared to higher action, the trade-off is that the lower you go, the more you sacrifice the instrument’s acoustic value. Notes will become stifled and choked because the strings simply don’t have enough room to vibrate and reach their full potential.

For most of us, the sweet spot is somewhere in the middle.

Do New Guitars Have Good Action?

Depending on build quality, new guitars may or may not have good action out of the box.

The fact is the vast majority of production instruments are set to factory specs. Though they tend to be within playable limits, they often need to be further refined to fit the player better.

Well known brands such as Martin, Taylor, Gibson, Fender and a host of others set very high standards for their instruments. This minimizes the chances of you getting a new guitar with poor action and playability.

On the other hand, there are an endless number of off-brand instruments that cover every conceivable level of quality.

At one end of the spectrum you’ll find new guitars that are literally unplayable, all the way over to those that play very well with great action, and everything in between.

Generally speaking, the better the grade of the guitar, the better your chances of it playing reasonably well directly from the manufacturer – or at least with minimal adjustments.

Why Does Action Change?

Over long periods, wood moves in ways you can’t see. The effects of time, pressure and humidity change the very nature of the guitar, this is why guitar action changes.

The effects of weather can have a very negative affect on instruments, particularly in extreme environments. Wood, the most common guitar material, expands and contracts with relative humidity which in turn causes structural issues such as cracking and joint separations.

Changing string gauges also changes the amount of compression or pressure on the guitar – which directly affects how the guitar plays.

For instance, going to heavier strings will pull the neck up which raises the strings creating a higher action. The reverse can be true if you change to a lighter gauge as well: the neck relaxes and the strings start to buzz requiring an action adjustment.

What’s the Difference Between Guitar Action and Guitar Setup?

Guitar action is the term used to describe how well a guitar plays, how easy it is to manipulate.

A guitar setup is more of a wholistic approach to the entire instrument. In other words, a setup covers all operational elements of the guitar from the tuners to electronics and everything in between.

For more information on all the elements that go into setting up a guitar, check out this guide.

How Much Does it Cost to Lower the Action on a Guitar?

The price to lower the action on a guitar – no matter what kind of instrument, will depend on how much effort has to go into making it right for the player.

Some guitars, especially better high-end brand name instruments, are fairly easy to get to play with nice low action because they’re just built better with better materials.

Consequently, lowering the action on a cheap guitar will likely cost more because of the extra work involved to get it to be more playable.

That said, a decent guitar setup will cost you somewhere between $50-$100 (USD) depending on your region, the amount of work required and the experience of the person doing the work.

Other Factors That Influence Action

Sensitivity to String Buzz

Along with simply being out of adjustment, other factors that influence guitar action include your own sensitivity to string buzz.

For example, an electric guitar that buzzes when played acoustically may not sound the same when plugged in. In other words, the buzzing doesn’t manifest through the amp.

Whether you can tolerate it or not is up to you.

On the other hand, an acoustic guitar with bad string buzz is outright annoying. For most players, whether acoustic or electric, this is the tipping point for an instrument that needs an action adjustment or complete setup.

Common Problems that Limit Action

Time, age and general build quality have a huge impact on how well a guitar plays. Sometimes, due to these same issues, a guitar’s action can be severely limited.

Moreover, a guitar that has underlying material or structural issues will be aggravated by an overly aggressive playing technique. Does this mean you should lighten up and change your style? Not necessarily.

You can have the guitar looked at or try to adjust it yourself, but best results will definitely be hampered by poor build quality.

Otherwise, common factors that cause a guitar to have compromised action include:

  • The condition of the frets
  • Distortions in the neck
  • Distortions at the body joint or poor neck angle
  • Poor quality, maladjusted or no truss rod
  • A lifting or cracked bridge on an acoustic guitar
  • Seized parts that should otherwise be adjustable
  • Mismatched factory parts

I would say the most common culprit would be the neck to body angle, followed closely by a neck condition that’s out of whack.

Luckily, electric guitars with bolt-on necks can have the neck-to-body angle corrected with a simple shim in the neck pocket. Some manufacturers, such as Fender and Peavey, even offer a micro-tilt feature to account for this – a small grub screw adjuster accessible at the base of the neck plate.

Why this feature is even necessary these days is beyond me. Considering the current state of precision manufacturing, surely a neck pocket can be milled to accommodate the compensation offered by an adjustable bridge – yes? (End of rant.)

On the other hand, acoustic and electric guitars with traditional set necks are another story. The only cure for these instruments with compromised neck-to-body angles is a costly neck reset.

Luckily, more forward-thinking manufacturers such as Taylor, Godin and others, design their guitars with this upcoming distortion in mind. They know pressure will eventually take its toll over time and allow for their necks to be relatively easily reset at a minimal cost.

The net effect? Better and more consistent action over the long term.

Mental and Physical Fatigue

Ever find yourself going in circles trying to chase perfection? Like when you’re trying to coax the most out of your guitar, and you wind up second guessing you work asking yourself, “Should it be this?.. or that?..”.

Not a good deal. Too many kicks at the can and you’ll lose sight of the goal.

Take a break, it’s good advice.

What to Do When Parts Don’t Match

Before I close out this section, I’d like to pass a long a curious, yet all too common situation that came across my workbench recently.

A regular client of mine had just purchased an electric guitar he wanted set up – a beautiful new Fender Vintera ’60s Jaguar in stunning Sonic Blue.

As much as he liked the guitar, he said it just didn’t feel right, even after a few well-practiced adjustments.

As soon as I picked it up I knew exactly what the problem was, I could feel it – a severe mismatch between the bridge radius and the fretboard radius.

As soon as I put it on the bench my suspicions were confirmed: the fretboard radius measured 9.5″ whereas the radius of the factory supplied bridge measured 16″!!…

Fender Vintera Jaguar neck radius
Fender Vintera Jaguar neck radius measuring 9.5″
Fender Vintera Jaguar bridge radius
Fender Vintera Jaguar bridge radius measuring 16″!

There was no way the action on this guitar was going to be satisfactory by merely adjusting the bridge height. Either the inner strings would always buzz, or the outer strings would always be too high with respect to the middle strings.

Ultimately, the bridge saddles needed some serious tinkering to get things to line up and the action where it needed to be.

After cutting the saddle slots and making the other critical action adjustments, the guitar played ridiculously well.

More importantly, the owner was extremely happy.

Not to bash Fender, but it would seem even the best of manufacturers have their blind spots. In this case, the negative effects of selecting over-generalized “off-the-shelf” parts is fairly evident.

Sadly, this is not the only time I’ve come across situations where mass production and end usage diverge – a beautiful Japanese-made Gretsch comes to mind.

I guess the point is, regardless of what a manufacturer says, check for yourself and don’t take anything for granted.

Common Items You Can Use for Measuring Action

There’s something to be said for keeping it simple. Not to downplay the importance of proper tools, but using materials at hand in a practical way does offer a certain convenience.

For instance, you probably have some spare change in your pocket or on the dresser, and every guitar player uses strings which come in specific gauges.

Both coins and strings can be used as tools for fine measurements. You just need to know their thicknesses.

Here are a couple of charts you can make use of for handy reference:

Coins: USD sorted by thickness

(Keep that spare change handy!)

blankHalf Dollar.085″2.15 mm
blankNickel.077″1.95 mm
blankQuarter.069″1.75 mm
blankPenny.061″1.55 mm
blankDime.035″1.35 mm

Guitar Strings: Common gauges and types in inches, sorted by thickness

(The next time you change your strings, keep the tag ends!)

Electric – Extra Light.
Electric – Light.
Acoustic – Light.
Acoustic – Medium.
Bass – Light.
Bass – Regular.

Summary of Key points

Regardless of the type of guitar, most instruments will follow the same general procedure to maximize action:

  1. Determine the current action of the guitar. This can be done by measuring the distance between the strings and the fretboard at the 12th fret.
  2. Decide on the desired action. This will depend on personal preference, as well as the type of music being played and your playing style.
  3. Adjust the truss rod to alter neck relief. The action through the middle of the neck will raise or lower depending on the amount of curvature.
  4. Check and adjust the nut height. The depth of the string slots will raise or lower the action at the headstock.
  5. Adjust the saddle for height and fretboard radius. Saddle height will raise or lower the action at the bridge.
  6. Fine-tune the action by making small adjustments to the truss rod, saddle, and nut as needed.
  7. Test the action by playing the guitar and observing any issues with comfort or sound quality.

Adjusting the action on a guitar can be a time-consuming process, but for any guitarist, it’s important for achieving the best playability and sound quality.

stars divider

Personal Thoughts, Notes and Observations

Just as there are many different kinds of people and sensitivities, there are that many interpretations of what “good action” could and should be. The type of guitar you play, the style of music you try to push out, your approach to playing etc.

My point is, there is no one perfect type of action thats serves everyone and every guitar. It’s very much a matter of personal preference. This is why I continually used the phrase “acceptable limits” in the adjustment procedures.

Should Action Look Right, or Feel Right?

From my own experience, and doing considerable additional research for this article, I found an overabundance of reliance on the technical aspects of measuring action.

Don’t get me wrong, you gotta have and make use of good tools. But at the end of the day, the ultimate judge in how well a guitar plays is the feedback that comes through your fingers – either it feels right or it doesn’t.

You don’t play with your eyes, you play with your hands. Think about it, which “sense” makes more sense when it comes to playing? Sight – or touch?

When it comes to setting a guitar’s action, I’ve been fooled by tools. Then I set them aside and let my hands, that tactile sense, tell me what’s really going on.

And it never fails.

Follow Steve Blundon:
Steve Blundon is a business owner, published author, former music teacher and active master guitar tech who's been servicing instruments for over thirty years. Visit Author's Page.

2 Responses

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    Great guide Steve. Super thorough, and I especially appreciate that you took the time to shoot all your own photos, make your own illustrations, etc. vs. just using stock photos or lifting them from other guitar blogs.

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