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If you’ve ever struggled to play a guitar with action that’s too high or too low, you definitely know it’s important to keep your strings at the correct height.
But maybe you’ve also wondered, whether guitar strings should all be the same height.
Guitar strings should all be about the same height from the frets, with some margin for the different thicknesses of the strings. When you look down the neck of most guitars, however, you’ll also notice that the strings follow an arc, and this is also important to preserve.
Let’s look at why your strings all need to be the same distance from the frets, how you can adjust your string height, and how the string radius can affect things.
Why Does String Height Matter On A Guitar?
If you’re new to guitar, you might not understand what the big deal about string height is. But the string height, also known as the action, is essential to both how a guitar plays and how it sounds.
If the action is too low on a guitar, you’ll have issues with buzzing noises when playing, which is caused by the strings hitting the frets when vibrating. If the action is too high, you’ll have difficulty pressing down the strings and you’ll notice notes and chords starting to sound wrong because the action has changed the guitar’s intonation.
Intonation refers to the match between the intended frequency of a note on the guitar and the actual pitch produced, which will vary slightly based on the actual length of the string.
This video looks at the physics behind guitar intonation and what guitar makers have to decide when building an instrument.
How Do You Measure Guitar String Height?
Measuring string height is very straightforward. Lay your guitar on its back on a flat surface, making sure the neck is well supported.
Place a ruler on the top of the 12th fret and measure to the bottom of each string in turn, noting how far from the fret each is. You need to check your measurements carefully, and it’s essential to use as high quality a ruler as possible.
Don’t rely on that unbreakable plastic ruler you’ve had since eighth grade. Use an engineer’s ruler or, better yet, a ruler designed for guitar setup, which would include things like string spacing measurements as well as regular measurements.
There is plenty of room to adjust to taste, but a good starting point for an electric guitar is 3/32nds of an inch, or 2.38 mm, on the low E string and 1/16th of an inch, or 1.59 mm, on the high E string.
If you’re playing an acoustic, aiming for 7/64ths of an inch, of 2.78 mm, on the low E string and 5/64ths, or 1.98 mm, on the high E string, is a good place to start.
The other strings should all be between the low E and high E strings in height, based on their thickness.
There is some room to move up and down based on your playing style, the particular guitar, and even the specific gauge or thickness you prefer. We’ll look at some ways to do that.
How Do You Adjust String Height On A Guitar?
There are a number of different things that can cause changes to a guitar’s string height, so it makes sense there are a number of different ways to make adjustments to string height.
Each change will affect playability, tone and intonation in different ways, and getting the right balance is essential to a good setup. Take your time and make small changes rather than big ones, especially at first.
How Do You Adjust The Height Of All A Guitar’s Strings At Once?
If your action isn’t right, you’ll want to adjust your strings, but you need to understand what’s causing the problem in the first place.
The first thing to check is always the guitar’s neck relief. A guitar’s neck will bow and straighten based on temperature and humidity, so the truss rod needs to be adjusted regularly.
With your guitar on its back on a flat surface, and with the neck well supported, hold down the low E string at the first and 14th fret. Check string clearance at the seventh and 12th frets, then repeat the process on the high E string.
There should be just a small amount of space between the bottom of the string and the fret. If there’s too much, your truss rod should be loosened, but if the strings touch either fret, you need to tighten the truss rod.
The truss rod is used to distribute the load strings put on the neck of a guitar. It helps introduce a back-bow, known as relief, into the neck.
This video from Fender shows how most guitars of similar type can have their truss rod adjusted.
Obviously, increasing the relief raises the strings while decreasing it lowers them.
But what if your neck is properly adjusted and your strings are still at the wrong height?
That’s where bridge adjustment comes in. Most modern electric guitars have individual string adjustment, which we’ll examine shortly, as well as the ability to raise or lower the entire bridge.
Relatively few acoustic guitars have either ability, though. Instead, you might need to adjust the saddle, which is what the strings cross before being anchored with pins or going into a tailpiece.
Some acoustic guitars, especially some Gibson models from the 1970s, actually let you adjust the saddle height using two screws. Most, though, require you to loosen the string tension and remove the saddle in order to change its height.
To lower it, you can sand off material slowly. If you need to raise it, you can either try a new, taller saddle or use thin shims under the saddle.
How Do You Adjust Individual String Height On A Guitar?
Some guitar and bridge setups make this easier than others. In general, a Tune-o-matic style bridge, which is often used on Gibson guitars and is common on a wide range of instruments, lets you raise or lower one side or other of the bridge, but raising and lowering individual strings is difficult.
This video looks at the process of setting up a Tune-o-matic bridge.
Fender electric guitars, on the other hand, normally have bridges with individually height adjustable saddles, but it can be difficult to make quick adjustments to the bridge as a whole.
Most modern hardtail and vibrato-equipped Fender guitars use similar bridge designs. For these, the height of each individual string is adjusted by two small adjustment screws.
Let’s run through raising or lowering the height on a bridge with individually adjustable saddles.
- Loosen string tension. You need to reduce the string tension enough that the saddles will move freely, but you don’t need to take them off entirely.
- Adjust the saddles using the screws to the left and right of each saddle slot. Keep careful track of how many turns you make so you can make the same number on the other screw.
- Repeat this for each string. If you take good measurements before starting you can get a rough idea of how much to adjust each string.
- Tune your guitar and re-check your action. Your best bet is to start with the strings higher than you want and lower them a little at a time until you hit your desired action.
If you need to make small changes to the height of one string, loosen that string slightly, make the adjustment and bring the guitar back up to tune. You don’t want to make many adjustments to the bridge saddle’s height or intonation with the string under full tension — that’s a recipe for a broken string.
How Do You Use A String Radius Gauge To Set String Height?
When you’re setting up an electric guitar with individually adjustable string height, you actually face a problem you don’t with other guitars.
For the most part, acoustic guitars and guitars that use Tune-o-matic or wraparound style bridges have a fixed string radius. That’s because the arc the bridge creates — which is needed to follow the radius of the fingerboard — is already set and saddle height isn’t adjustable.
You have to be more careful with individual string height adjustment. That’s because while the strings on your guitar look like they’re all in a line, they’re actually all at slightly different heights.
And while they look pretty flat, nearly all fingerboards and saddles are actually radiused, meaning they follow a curve that would, if you kept going, create a circle.
The size of that circle is the diameter of the radius of the neck.
The art and science of deciding on a fingerboard radius is too complex to get into here, but in general, more curved radii make it easier to play chords and barre the fretboard, but they also mean you can’t bend notes as far without running into the frets.
In general, Fender guitars have smaller radii, making them more curved. Historic examples were mostly 7.25 inch radius, while more modern ones are often 9 inch radius.
Do a quick search online and you’ll find a number of free printable templates for radius gauges. Simply print one out, cut it out according to the instructions and you’re ready to use it.
Each arc will be labeled with its size, and to make sure your string radius is right, use the gauge to make sure the radius of the neck matches the radius of the strings just above the bridge saddles. Again, be sure to loosen the string a bit before adjusting the height.
If you leave your strings in a different radius than the neck, you’ll run into problems with playability, including notes starting to “fret out,” or buzz, as you go up the neck, as well as with the intonation.
The fact that most guitars don’t actually have a flat fretboard can make it confusing when setting up a guitar. Most fretboards have some kind of radius, which makes playing much more comfortable.
On many guitars, the radius of the neck is matched by the bridge automatically, and without a way to change that. On some guitars, though, you have to match that radius.
While that makes a guitar’s strings follow an arc, when you measure, you’ll actually find that the strings are almost all the same height from the top of the frets.
I’ve been a musician, particularly a guitarist, for more than 25 years. I love writing about guitars, gear, recording, music in general and more.