The Complete Guide To Guitar Nut Height For Electric, Acoustic, Bass, And Classical Guitars

Section One: Guitar Nut Height & Nut Height Gauge

What Is The Importance Of My Guitar's Nut Height?

The height of the strings at the nut is a critical measurement to the way a guitar is going to play and sound. The nut is typically made of bone, plastic, brass or graphite. It governs the intonation in the low registers, the playability, and tuning stability. If the height of the strings at the nut is too low, then the open string will buzz. If the height is too high, then the string will be hard to push down, so your action really suffers. As you stretch the string, it goes sharp before it touches the first fret.

When Should I Check The Nut Height Of My Guitar?

You should check your nut height if you are experiencing string buzzing, intonation issues, too high or low string action, after you adjust your string action, and seasonal weather changes.

What Steps In The Setup Process Must Be Done Before I Check My Nut Height?

Checking your nut height is the fourth step in MusicNomad’s KEEP IT SIMPLE, SETUP (KISS) process. You check nut height after adjusting your truss rod and setting your string action and radius.

What Tools Do I Need to Measure and Adjust My Guitar's Nut Height?

There are a few tools you will need to check and adjust your guitar's string action.

A Nut Height Gauge to precisely measure the distance between the fret and the string at the 1st fret. MusicNomad's gauge includes measurements for electric, acoustic, classical, and bass guitars.
Nut Files, preferably diamond coated files. You will need a file with a smooth, precision cut. MusicNomad's files cut & polish slots simultaneously and do not drift like common toothed files.

How Do I Measure My Guitar's Nut Height?

First, select the proper size nut height gauge (see below for common measurements). Then put the guitar playing position, making sure it’s in tune. Slide the gauge between the 1st fret and the first string (low E-String on electric guitars).

If the gauge does not touch the fret and the string, then we know that your string is too high, and you would need to lower the string slot in the nut. If the gauge touches the fret and string heavily, you'll know that the string is lower than it needs to be. Note that if the string does not give an open buzz, you can leave it alone.

However, if you have a heavy touch on both the top and the bottom and the string buzzes open, you will need to shim the nut up, fill the slot, or have the nut replaced. Any competent local luthier should be able to help you out. Just remember that if you put the gauge on top of the fret and it slides in and perfectly touches the string and the top of the fret, then you know that your string is adjusted correctly, and you don't need to take any action. Once you measure your low E string, measure your D, G, B, and high E strings. The process is similar for bass, acoustic, and classical guitars.

If you are unsure if the gauge is touching, tap on the string and listen for a little click. If you can hear a click, then you have a little bit of space between the string and the fret.

Below is a video that shows you this process.

Note: Although the recommended nut heights will result in a great playing instrument, we have provided smaller and larger gauges to accommodate a desire for lower action or a heavier pick attack. You may want to experiment to find what works best for you.

What Are The Recommended Nut Heights For My Guitar?

For Electric Guitars & Acoustic Guitars:

Low E String & A String (0.020"/0.50mm)
D String & G String (0.018”/0.45mm)
B String & High E String (0.016"/0.40mm)

For Bass Guitars

E String & A String (0.020”/0.50mm)
D String & G String (0.018”/0.45mm)

For Classical Guitars

Low E String & G String (0.020"/0.50mm)
A String & B String (0.018”/0.45mm)
D String & High E String (0.016'/0.40mm)

Note: If you use a heavy attack on an electric or acoustic guitar, start with 0.022" (0.55mm) on your low E-string, then 0.020" (0.50mm) on your D and G strings, and finally 0.018" (0.45mm) on your B and E strings. If you have a lighter attack, you can drop down and use 0.018" (0.45mm) on your E and A strings, 0.016" (0.35mm) on your D and G strings, and 0.014" (0.35mm) on your B and E strings.

How Do I Know What String Size/Gauges Are On My Guitar?

You can accurately measure the thickness of each string using a digital caliper or micrometer. Those tools will give you the exact gauge of each string. However, If you need clarification and do not have the right tools, a local guitar shop or luthier can measure your strings for you. It is highly recommended to save the string package when you change your strings to help keep track of what strings are on your guitar.

Section Two: Nut Filing & Adjusting

What Are The Most Important Factors To Consider When Buying A Nut File?

Ensure that whichever nut file you use has an ergonomic handle for total comfort and control of your cut. Otherwise, you could risk accidentally cutting the fretboard. Having a nut file that is diamond coating with the right size is essential.

Diamond coated nut files are recommended because they both cut and polish at the same time and do not drift like toothed files. Having the correct size nut file is also important. If you use a file that is to large, the slot can become so large that the string vibrates in the slot, causing a buzz. If you use a file that is too small, the slot will be too tight, causing tuning issues.

What Nut File Should I Use For Each String Size?

The general rule is that the file should be the same size as the string, up to no more than .003" - .004" larger than the string size and for bass strings you can run your nut file size up to .005" larger than the string size. In other words, for a .026" string you would use the .028" file; for .011" string you use the .013" file; for the .080" string you use the .085" file and so on. If you go much larger, the slot can become so large that the string vibrates, causing a buzz. If you use a file smaller than the string, the slot will be too tight, causing tuning issues.

MusicNomad’s String Guide list many of the common string brands and sizes and recommends the correct Nut File Sizes for those strings.

How Do I Adjust My Nut Height?

After finding the nut file size you need, loosen the string and lift it out of the nut slot.
Place the nut file in the nut slot with a slight downward angle towards the headstock
Using light pressure, slide the file back and forth.
Blow out the slot to remove the debris.
Return the string to the slot, retune it, and recheck the height.
Repeat the process as needed for each slot.

Tip: Color the bottom of the string slot with a pencil to see what you are removing. After setting the nut height, lubricate all string touch points with MusicNomad's TUNE-IT Lubricant.

How Do I Adjust My Guitar’s Nut Height On A Locking Nut?

For guitars with a locking nut, you can’t file the individual string slots to correct any action problems. You have to either take the material off the bottom of the nut to lower it or put shims under the nut to raise it. One issue with locking nuts is that you may be unable to make every string perfect because you can’t adjust the individual nut heights. Therefore, you may have a couple of strings that are a little high or a little low. You should be fine if none of the strings are buzzing.

Loosen all the strings and unscrew the nut from the neck. Check to see if there are any shims underneath. If there are any shims, remove them as well.
Raise the tremolo and stick a small piece of wood (or similar material) under the back to keep it from sliding.
Loosen all the strings to reduce all tension in the string and take off the nut locks.
Take an Allen wrench (or Philips head screwdriver) and adjust the screws.
Put the nut back into the slot and screw it back down.
Re-tune and measure the rest of the strings if necessary.

Section Three – Common Questions & Issues

What Issues Can Occur If My Nut Height Is Too Low?

If the string height at the nut is too low, then the open string will buzz and can create intonation issues with your string as well.

How Do I Raise My Guitar's Nut Height?

If you find that your nut height needs to be raised there are a few options. You can take it to a qualified repair shop, but you can also use a nut repair powder such as The Nut Rescue Kit from Music City Bridge. The product's three shades help match most nuts: Black, Cream, and White

How To Use The Nut Rescue Kit

Clean the slot with a file.
Score the slot with a razor.
Use the applicator included to fill out the slot with Nut Rescue. Make sure to tamp it down gently.
Touch the slot with a bead of thin superglue.
File to the preferred height.

Would My Nut Height Change With My Pick Attack?

If you have a heavier pick attack, you want to increase your nut height to avoid fret buzz issues. If you had a very light pick attack, reduce your nut height to give you a lower string action. MusicNomad’s Precision Nut Height Gauge does provide extra gauges to help increase or decrease your nut height measurements from the most common nut height.

What Issues Occur If My Strings Are Too Tight In the Nut Slot?

If your strings are too tight in the nut slot, it is likely that the string with ping and cause intonation issues. In those cases, consider widening the nut slot. You can do this yourself with a technique called file rolling or you can take it to a qualified repair shop. See below on how to fix a tight nut slot.

How Do I Widen My Guitar's Nut Slot?

To widen your guitar nut slot, you can do a technique called rolling the file. You can cut the file down the side of the nut slot and open up the nut slot just a bit to create more clearance for the string without raising the nut slot up to the next size file.

Roll the file slightly to the right, put a bit of pressure going down the nut slot's left wall, and stop when you get to the bottom so as not to go any lower. You would then roll the file slightly to the left, put a little pressure down the right wall of the nut slot, and stop when you get to the bottom of the slot so as not to go any lower. It's important that you do not want to open the slot too much or make the slot lower. You can also use MusicNomad's TUNE-IT Lubricant in the nut slots as a lubricant.

Do I Need To Recheck My String Action Height After I File My Guitar Nut?

No, you do not need to recheck your string action height after filing your guitar nut. If you follow the KEEP IT SIMPLE SETUP method, there is no need to backtrack in the guitar setup process.

What Is The Proper Guitar Setup Step-By-Step Process?

Depending on the type of guitar you will want to follow these steps in order to setup your guitar. MusicNomad's Keep It Simple Setup (KISS)™️ helps you properly setup your guitar.