Guitar Strings Guide: Sizes & Measurement

Published Categorized as Buying Guides, Guitar String Reviews

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For guitarists, With all the focus on amps, pedals, and other gear, it can be easy to lose sight of the smaller things. While guitar strings are some of the least expensive pieces of gear, they also are some of the most important when it comes to both tone and playability.

But how do you choose the right strings? There’s a wealth of materials and guitar string sizes out there. And in this article, we’ll tell you all you need to know to choose the right strings for you.

Table of Contents

Guitar String Guide: All You Need to Know

As a general disclaimer, we will mostly be focusing on strings for six-string guitars, but much of the advice in this article is still useful for extended-range guitars, 12-string guitars, and four-string tenor guitars.

Do Guitar String Sizes Matter?

Choosing guitar strings might seem like a daunting process. Plenty of people just pick out acoustic strings or electric strings without paying attention to the size (or gauge) of the strings. And if you’re new to the guitar world, it’s easy to fall into the trap of thinking a string is just a string.

But if you’re serious about how your guitar sounds at all, string sizes really do matter. And as we’ll see in a moment, string size impacts many aspects of playing guitar — from tone to playability to finger fatigue.

What Do Guitar String Gauges Mean?

Perhaps the most important thing to look at when choosing guitar strings is the string gauge. The gauge of a string refers to its diameter or thickness. You generally can’t tell a string’s gauge just by looking at it, so string companies label the gauges of every string in a pack.

You’ve probably heard some players refer to sets of strings as 9’s, 10’s, etc. Strings are measured in thousandths of inches, and string packs are often described using the gauge of the thinnest string in the pack. Many electric guitarists play with 9’s. That means that the high E string of that pack has a diameter of 0.009 inches, or nine thousandths of an inch. Usually, 9’s (on electric guitars) are considered to be extra light strings.

What Are Standard Guitar String Sizes?

When most people reference sizes of guitar strings, they mean the specific gauges of strings. Still, there are some general string size types that you can consider before getting into specific gauges. When people talk about string sizes, you may hear them reference some of these:

  • Super Extra Light
  • Extra Light
  • Super Light
  • Light
  • Medium
  • Heavy

These are fairly general terms — some manufacturers use slightly different names (like “extra light” instead of “super light”) to describe strings of the same or similar gauges.

Common Guitar String Gauge and Sizes

Guitar Strings Guide Sizes Measurement_Six Strings Acoustics

Here’s a guitar string thickness guide to some common gauges for acoustic and electric guitars. The string size is listed alongside a pack’s typical string gauges from high E string to low E string.

Typical Acoustic String Gauges

  • Extra Light – .010/.014/.023/.030/.039/.047
  • Custom Light – .011/.015/.023/.032/.042/.052
  • Light – .012/.016/.025/.032/.042/.054
  • Medium – .013/.017/.026/.035/.045/.056
  • Heavy – .014/.018/.027/.039/.049/.059

Typical Electric String Gauges

  • Extra Super Light – .008/.010/.015/.021/.030/.038
  • Super Light – .009/.011/.016/.024/.032/.042
  • Light – .010/.013/.017/.026/.036/.046
  • Medium – .011/.015/.018/.026/.036/.050
  • Heavy – .012/.016/.020/.032/.042/.054

This string chart guitar is just intended as general advice. Plenty of manufacturers make “custom gauge” strings that deviate from your typical gauges.

But now that you know a little more about string gauges, how do you know which to select? As you look at different sizes, it’s a good idea to consider the benefits and drawbacks of both light and heavy strings.

Light Strings

They make it easier to play quickly
They don’t cause much finger fatigue
They make string bending and vibrato easy
They have a bright sound that a lot of players like
They’re more prone to string breakage
Some players consider their tone to be too “tinny”

Heavy Strings

Pros Cons
They have a “meaty” tone with a lot of presence
They have more sustain
They’re better for drop tuning
They are less prone to breakage
They cause more finger fatigue
They make vibrato and string bending more difficult

You probably noticed that acoustic guitar strings tend to be a bit heavier than electric guitar strings. Since acoustic guitars need to be able to be heard without being amplified, they tend to need larger strings. Heavier strings also produce a fuller sound — if you were to put very light electric strings on an acoustic, the sound would likely be overly tinny with a poor bass response.

Heavier strings are also part of why many people consider acoustic guitars to be harder to play than electric guitars. Acoustics tend to have both higher action and heavier strings than electrics, so it takes more force to fret both notes and chords.

How Do I Know What Size Strings Are on My Guitar?

Taking guitar string measurements of strings that are already on your guitar is next to impossible without a special tool. But if you really want to know your string gauge and can’t figure it out another way, a micrometer or slide caliper will work. These tools are fairly inexpensive and very easy to use, and you can find them online or in most hardware stores.

If you purchased your guitar new, it’s worth taking a look at the specs. Most manufacturers will list the exact type of strings they put on their new guitars.

If you know any experienced guitarists, they may be able to help you determine the string gauge, too. Some players can get a feel for different guitar string gauge sizes just by looking at your instrument.

What is the Most Common Guitar String Gauge?

If you aren’t sure which strings would suit you best, it may be helpful to know what string gauges are the most popular. Keep in mind that this refers to popularity across genres. For instance, even though lighter electric guitar strings are more popular overall, heavier strings are more popular among metal players.

Most acoustic guitars come strung with 12’s. This gauge is a versatile one — it doesn’t have the noticeable brightness of lighter strings, but it’s easier on your fingers than the heavier gauge strings. It effectively delivers the best of both worlds.

As far as electric strings go, 10’s are the most popular gauge. They offer a balanced tone without sacrificing playability. Their sound is a bit beefier than that of 9’s, but they’re still light enough to allow for easy string bending. They don’t cause excessive finger fatigue, either.

How Strings Affect Your Tone?

Guitar Strings Guide Sizes Measurement_Six Strings Acoustics

Guitar string width certainly has an impact on your tone. But before you select a gauge, it’s a good idea to get an in-depth sense of how your strings can shape the sound and feel of your playing.

Heavy Strings

Let’s start with heavier strings. These strings produce a sound that plenty of players describe as “darker” or “heavier.” They also tend to be louder and have more sustain. That’s because heavier strings have greater string tension. When you pick or strum the strings, their greater tension means that they take longer to stop vibrating than lighter strings do.

It’s worth noting that the higher tension of heavier strings also makes them a good choice for drop tuning and alternate tunings. If you like to venture away from standard tuning, heavier strings can help you avoid string buzz and other potential pitfalls.

Heavier strings tend to have a warmer sound than thinner strings. They also offer more powerful bass and midrange response. If you play folk, blues, or other relatively mellow genres of music, you might find that these strings work best.

If you prefer slower playing with a real sense of emotion and atmosphere, these strings are likely to produce the tone you’re looking for. In particular, they work beautifully for slower soloing. In a fast guitar solo, you probably aren’t worried about sustain. But in a slower solo, you need to let each note really ring out. Thicker strings let you do that.

Light Strings

Now we’ll take a look at how lighter strings shape your tone. Lighter strings of course create a bright tone — that means that they emphasize treble and midrange frequencies. The sound of lighter strings is sometimes described as being “clear” or “crisp.” If you like a lot of top-end sparkle, they’re a good choice.

When comparing this tone to that of heavier strings, it may help to think of strings as being analogous to tonewoods. Lighter strings are more like spruce or maple. They’re bright and responsive, and they have a definite crispness to them. Heavier strings are more like mahogany — they have a mellower tone that is more “fuzzy” than crisp.

Light strings exert less tension on the neck, so they don’t have the same sustain as heavier strings do. Many of us look at sustain as being a unilaterally good thing. But choosing the right strings is a tradeoff. If you value the speedy playability that lighter strings afford you, sacrificing a little bit of sustain is generally worth it.

Guitar Strings Materials

The electric and acoustic guitar strings chart above gives you an idea of what gauge to choose. But what about string material?

Acoustic Guitar String Materials

Like electric guitar strings, most acoustic strings are made with steel cores. But the winding material used over that steel makes a major difference when it comes to tone. Most acoustic guitar strings are wound with one of two materials: 80/20 bronze or phosphor bronze.

The wrapping material known as 80/20 bronze has been around since the 1930s, although it’s still widely used today. The “80/20” in the name refers to the metal alloy used to wrap them — it’s made of 80% copper and 20% zinc. The combination of copper and zinc creates brass, so technically, the strings should probably be called 80/20 brass. These strings create a classic tone that is frequently described as “sparkling.” But they do have a downside — 80/20 bronze strings become corroded very quickly.

Players who prefer to not have to change their strings as often might be more interested in phosphor bronze strings. These strings are made mostly of copper, but they have around 10% tin and a small percentage of phosphorous. Phosphor bronze strings aren’t quite as bright as 80/20 bronze, but they’re a great choice for those who like a softer sound. They don’t corrode as quickly as 80/20 bronze.

There are several less common choices of string materials, too. Some manufacturers produce specialized alloys that offer a different sound than 80/20 bronze or phosphor bronze. Silk and steel strings are a little less common, but they are a good option for newer players or those with very sensitive fingers.

Classical guitars do not use the same type of strings that steel-string guitars use. Traditionally, they were strung with natural gut strings usually made from cattle intestines. Now, most classical guitar strings are made of nylon or similar materials. Nylon strings sound almost just like gut strings, but they are much cheaper and easier to produce. In many cases, the bass strings are wound with silver.

Electric Guitar String Materials

Electric guitar strings are made similarly to acoustic guitar strings, and they usually have steel cores. However, since they need to be magnetically reactive with the pickups of an electric guitar, these strings have different wrappings.

Most electric guitar strings are wrapped in nickel-plated steel. Steel tends to produce a sound that is bright and snappy, and nickel produces a warmer tone, so the combination is balanced and versatile.

Players who prefer a mellower sound might prefer strings wrapped in pure nickel. Nickel was more widely used on vintage recordings, but it also has its place in modern music. If you sometimes find the sound of your guitar to be too harsh, the smoother sound of nickel strings may be enough to balance it out.

If you like a very bright, snappy sound and value strings that resist corrosion, you might like steel-wrapped strings. They aren’t quite as common as nickel or nickel-plated steel strings, but they’re ideal for creating an energetic, modern sound. 

These three string types are the most common, but there are plenty of other materials out there. Some players like cobalt strings, as cobalt tends to have a more powerful electromagnetic connection to your pickups. This results in a more powerful output. Chrome strings are ideal for players who prefer a very warm tone, and they are often favored by jazz players and blues guitarists. And if you need extra-strong strings that impart some extra brightness to your tone, you might like titanium strings.

Coated Strings

For players who want to really extend string life, coated strings are an option. Coated guitar strings are made just like any other strings, but they have a special polymer coating. Most coated strings are made for acoustic guitar strings, as they corrode more quickly than electric guitar strings.

The polymer coating works by shielding the strings from dirt and oil. Since the coating is slippery, wiping off dirt and oil is easy. And since the coating protects the strings from the air, they won’t corrode as fast.

Coated strings do have their downsides, though. Some guitarists say that they make the strings sound “dead.” Their slippery feel has the benefit of reducing finger squeaks, but it also can cause your fingers to slip off the strings, especially when string bending.

Winding Method

Guitar Strings Guide Sizes Measurement_Six Strings Acoustics

You already know that most guitar strings have a steel core and a metal winding. But even the winding method used has an impact on tone and playability.

The vast majority of strings are roundwound — the winding around the string gives it a round cross-section. These strings produce an overtone-rich sound with lots of sustain. However, they’re more prone to producing finger squeaks and pick noise.

Flatwound strings have a flat wire wrap that makes each string more like a ribbon than a cord. They are much less common than roundwound strings, but they are common in the jazz world. Flatwound strings have a more thumpy character with less sustain, and they place more emphasis on the fundamentals (the actual notes you play) than it does on the overtones.

If you’re looking for a hybrid string type, you may want to consider half-wound strings, also called groundwound strings. These strings offer some characteristics of flatwound strings and some characteristics of roundwound strings. On the side of the string facing the fretboard, they are round. But the top is flat, so you get a smooth feel and fewer finger squeaks. These strings are very uncommon, and there are far fewer options out there than there are of roundwound or flatwound strings.

Best Guitar String Brands

There are plenty of guitar string brands out there, but the sheer number of choices can make it tough to know which one to choose. It can be helpful to have a general sense of which brands have a good reputation. Here are some of the best brands to choose from:

  • Ernie Ball
  • GHS
  • D’Addario
  • Martin
  • Fender
  • Elixir

FAQs (Frequently Asked Questions)

Now that we’ve gone through our primer on guitar strings, you might still have some questions. After all, the more you learn about guitar strings, the more you realize there is to learn! Here are some quick answers to some common questions.

How Much are Guitar Strings?

Playing guitar can definitely become an expensive hobby. But luckily, compared to most types of guitar gear, strings are very affordable. On the very inexpensive end, a pack of strings can be about $3-$4. And even the most expensive string packs almost never go over $12-$15.

Generally, it’s a good idea to spring for higher-quality strings. After all, the price difference between a cheap pack of strings and a high-quality one is just a few dollars. Those few dollars can make a major difference in your tone and tuning stability. 

Once you find quality strings that you like, you may find that purchasing multiple packs at a time is a good way to save money over time. Many music supply companies offer multi-pack deals, and string manufacturers themselves will sometimes run promotions where you can save a significant amount of money.

Can You Put Any Strings on a Guitar?

Not really. For instance, putting acoustic strings on an electric guitar is not a great idea. 

Electric guitar strings need to be magnetically reactive in order to work with the pickups on a guitar. Usually, the first two strings (the ones that just have an unwound steel core) are reactive enough to sound like regular electric guitar strings. 

But the winding on the other four strings is usually made of bronze. Bronze is not magnetically reactive. The steel core may still be able to react with the pickups to some extent, but the signal will be very weak. So if you string an electric guitar with acoustic strings, you will have a very uneven signal — some strings will sound much louder than others.

You can put electric strings on an acoustic, though. The sound isn’t for everyone, but it produces a unique, snappy tone. If you’re someone who likes to experiment with different musical genres and/or different guitar tones, it’s worth trying out.

Some players like to substitute nylon strings for steel strings on steel-string guitars — this was somewhat common among folk musicians of the 1960s. It’s something you can do, but be careful when selecting your strings — many nylon strings are designed to be looped through the bridge of a nylon-string guitar, so they aren’t compatible with the bridges found on steel-string guitars. If you intend to put nylon strings on a steel-string guitar, be sure to get nylon strings with ball ends. That way, you can secure them with the bridge pins of a typical six-string guitar.

Are Light or Medium Guitar Strings Better?

The best size of guitar strings for you depends on both your playing style and desired tone. One of the main things to consider is playability. Lighter strings are easier to bend, and they require less pressure to fret. So if you play long sets, do a lot of string bending, or just want to avoid finger fatigue, you might want to consider lighter gauge strings. Lighter strings also produce less tension on the neck, and that can prove to be advantageous over time.

Medium strings can be more of a challenge when it comes to fretting and bending. But some players prefer the fuller, warmer sound they produce. Lighter-gauge strings produce a sound that some players describe as “bright” and other players describe as “tinny.” Whether that’s a good thing or not is purely a matter of taste. If you play especially forcefully, you might prefer medium guitar strings, as they are less prone to breakage.

Medium strings are probably the better choice if you like the playability of lighter strings but prefer a sound that is slightly warmer. They offer a good compromise between heavy and light strings.

If you’re choosing strings for the first time or are just trying to figure out what you like, choosing between light or medium strings can be tough. If you want some extra guidance, many manufacturers offer a guitar strings gauge guide for their specific brands. These guides often will offer commentary on how the gauges sound in relation to one another.

Which Guitar Strings are Easiest on the Fingers?

When it comes to string gauges, lighter gauge strings tend to be easier on your fingers. For one, they take less force to fret. And if you have sensitive fingertips, they often cause less irritation that way.

Some string materials are harder on your fingers than others. There’s a reason many younger children start out learning on nylon-string guitars. Nylon strings are softer and cause less finger pain and irritation. And since nylon-string guitars have much lower string tension, they tend to be easier on your fingers than most other string types.

The steel strings found on most acoustic and electric guitars tend to be the hardest on your fingers — both because they’re made of metal and because they have higher string tension. But once you’ve developed adequate calluses, they aren’t likely to bother you. 
Some learners like to ease into playing steel-string guitars with silk and steel strings. This material mixture has a softer feel, but it still sounds much like pure steel strings. Some players move on to regular steel strings once their fingers have acclimated, but others like the mellow tone enough to continue playing with silk and steel.

How Often Should You Change Guitar Strings?

Even the best strings eventually accumulate dirt and oil, and they then start to sound dull. But how often should you change strings in order to keep your guitar sounding its best?

Knowing when to change your strings isn’t an exact science. But most players and instructors recommend changing your strings every three months or every 100 hours of practice. Of course, most people probably don’t count their practice hours. But if you play every day or for hours at a time, you’ll probably want to stick to the three-month rule of thumb. If you only play occasionally, you can likely stretch that amount of time.

There are several factors that may affect how long you can go between string changes. Corrosion and the buildup of dirt and skin oil will cause strings to wear down faster. Wiping down your strings with a special string cleaner each time you play will help them last longer. And if you live in a humid area, moisture in the air is very likely to speed up corrosion as well. Since their coating resists dirt and corrosion, coated strings generally need to be changed less often.

Once you get used to how your guitar sounds with a given type of strings, you’ll probably be able to tell when your strings need to be changed. Older strings tend to sound more flat and dull.

How Long Do Guitar Strings Last?

Of course, if you only play casually, you may just leave your strings on indefinitely and only change them when they break. It’s impossible to predict exactly when a set of strings will break. But if you don’t play very forcefully and if your strings aren’t subjected to excessive humidity, they may well last for a year or more without breaking.

Wrapping Up

Hopefully, you now have some idea of what guitar strings are right for your playing style and tone. But remember that finding the right strings can be a process; don’t be afraid to try different gauges and materials. As your playing evolves, you may find that your choice of strings does, too.

For a more general guide on the sizes of acoustic guitars, click the link.

By Nate Pallesen

Nate is just your average (above average) guitar player. He's no Joe Satriani, Jimi Hendrix or Jimmy Page - wait this site is about acoustic guitars (sorry) He's no Django Reinhardt, Chet Atkins, or Michael Hedges, wait? who!? He's no Robert Johnson, Eric Clapton or Ben Harper - more familiar? Anyway you get the point :-)


  1. What acoustic strings do you recommend for older thin skin players? I play Taylor and Martins acoustic guitars but the Elixer light strings are hurting my fingers.

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