Why Do Guitar Strings Have Different Thicknesses?

When I was little, I remember marveling at how hard the strings on a guitar were to press down and how thick they seemed against my fingers.

Maybe you’ve wondered, like I did then, why do guitar strings have different thicknesses?

If you have two strings of the same length at the same tension, a thicker string would produce a lower pitch. Therefore, most guitar strings are of different thicknesses so they can produce different pitches. Other factors like the composition of the strings and the tension the string are tuned to also affect the pitch.

That’s the quick answer but let’s take a closer look.

How Do Guitar Strings Work?

Sound is just a vibration in the air, and the rule is: the faster the vibration, the higher the pitch.

In a guitar, like other string instruments, each string is held in tension, and the vibration of the string creates the sound. The tuning mechanism lets you adjust that tension, which changes the pitch the string produces when played.

While the actual thickness of the string plays some role in the pitch it produces, the main determining factor is the tension the string is under and the frequency at which the string vibrates.

In fact, any two strings that vibrate at the same frequency would produce the same pitch.

One way to raise the pitch a string produces is to increase the tension, the other is to shorten its length. This video shows how the latter works:

In practice, though, thinner strings can be tuned to a higher tension than thicker ones, meaning they can vibrate faster and produce higher pitches. But too much tension on a string causes it to fail — usually by breaking — and you don’t get any note at all out of a failed string. Here’s a look at some other reasons strings might break.

The way a guitar string affects how much tension a string can withstand as well as how much tension it requires to make it sound the correct pitch.

Why Are Some Guitar Strings Thicker Than Others?

Generally speaking, if you have two strings of the same length at the same tension, a thicker string would produce a lower pitch. In Standard Tuning — E A D G B E — the low E and high E strings are under similar amounts of tension.

In a set of light gauge electric guitar strings, the high E string is usually .009″ and a plain wire, while the low E string is usually .042″ and wound — quite a difference.

If you’re wondering whether you could tune a guitar using only one thickness of string, you probably could, but it would almost certainly sound terrible.

We’ve already gone over what happens if you put a string under more tension than it was designed to handle — it breaks.

A blog post from a few years ago looked at what it would take to tune every key on a piano to middle C and determined that just tuning the lowest string that high would produce 20,000 pounds of force. Even if the string were unbreakable, that kind of tension would destroy any instrument.

What happens when you put a guitar string under less tension than it was designed to handle?

If you can make it produce a pitch at all, it won’t sound very good.

Try this experiment: Tune the second-lowest string — the A string in Standard Tuning — down a fifth so it’s playing the same note as the low E string. Note the different sounds the two strings produce.

The pitch is the same, but the thinner string sounds looser and less resonant than the thicker one, because it’s not under as much tension. It might sound OK, but imagine taking the third string — D in Standard Tuning — and tuning it all the way down to the same E as the lowest string.

That would almost certainly make a buzzy, dull sound.

That has to do with how strings are made. They’re engineered to be under a certain range of tensions, and anything outside of that just won’t work.

What Is String Gauge?

String gauge, which is another way of saying string thickness, gives players a sense of what a set of strings will be like to use.

As we saw above, thicker strings need to be at a higher tension to produce the same pitch as a thinner string. That also means, generally speaking, they’ll take more force to press down.

When dealing with the small differences between string gauge sets, the changes aren’t very much, but if you’ve ever picked up a guitar strung with much heavier gauge strings than you’re used to, you definitely noticed the difference.

Sets of strings are can be labeled in different ways, all of which have to do with thickness. Some strings are called Light, Medium or Heavy, while other sets with the same string thickness, might be sold as .010″s or .010-.046.

Here’s a quick breakdown of some common string gauge sets for both electric and acoustic guitars.

Common string gauge sets

Electric Guitar	E (Low)	A	D	G	B	E (High)
Extra Light	0.038″	0.030″	0.021″	0.015″	0.010″	0.008″
Light	0.042″	0.032″	0.024″	0.016″	0.011″	0.009″
Regular	0.046″	0.036″	0.026″	0.017″	0.013″	0.010″
Medium	0.048″	0.037″	0.027″	0.018″	0.014″	0.011″
Heavy	0.054″	0.042″	0.032″	0.020″	0.016″	0.012″
Acoustic Guitar
Extra Light	0.047″	0.039″	0.030″	0.023″	0.014″	0.010″
Light Strings	0.052″	0.042″	0.032″	0.023″	0.015″	0.011″
Medium	0.053″	0.043″	0.032″	0.025″	0.016″	0.012″
Heavy	0.056″	0.045″	0.035″	0.026″	0.017″	0.013″

How Does The Thickness Of A Guitar String Affect The Sound?

For the most part, a thicker guitar string will produce a deeper, fuller sound than a thinner one, but there are other things that go into that, as well. The material a string is made of will have a dramatic effect on tone.

One great example of how string composition can have as much or more of an effect on sound than thickness is a classical guitar. Originally, classical guitar strings were made from animal intestine — if you’ve ever head someone say gut-string, that is what it’s referring to — but modern classical guitar strings are made from nylon.

The high E string on a classical guitar is often about .028″, which is nearly as thick as the A string in a set of extra light gauge electric guitar strings. Because of the different way nylon and metal hold tension, however, it’s tuned much higher and it sounds very different.

You can hear the different tone a nylon string guitar makes in this video, which gives a basic introduction to playing techniques.

Part of the reason for the different tone from a nylon string guitar has to do with the way the guitars themselves are made, while some has to do with the composition of the strings and the way the material used holds tension and how it vibrates.

There are some ways that thickness directly affects the tone of your playing, at least as much as what the strings are made of. Many rock virtuosos have used light gauge or extra light gauge strings, particularly if they liked to bend notes.

Like we covered before, thinner strings require slightly less tension than thicker ones, so a .009″ string is easier to bend than a .011″ string. The lower tension also makes them more flexible, so they can be bent further. Here are some other ways to make string bending easier.

There is a lot that goes into the tone a guitar produces, from the guitar itself to the kind of strings to their thickness. The reason there are so many choices is because different strings work best for different purposes- whether that’s to target a specific style or to find the right match for a specific guitar.

The best way to find out what works for you is simple, and it’s fun — play guitar more. That’s just good advice in general.