Tennis String Gauge and Its Impact on Performance

If you’re just getting started with tennis string one of the helpful attributes to understand is tennis string gauge or the thickness of the tennis string and how it impacts performance.

While rather basic in concept many players rarely consider string gauge and therefore don’t fully reap the benefits of stringing their racquet with the best gauge for their level and style of play.


Let’s start by taking a look at the different gauge currently available for tennis string.

String Gauge Measurements

As I mentioned tennis string gauge is the thickness of a string, therefore we can get the measurement simply by taking the diameter of the string.

The following table outlines the different types of string gauge currently available.

Gauge 19 18 17L 17 16L 16 15L 15
Min (mm) 1.00 1.10 1.16 1.20 1.22 1.26 1.34 1.41
Max (mm) 1.10 1.16 1.20 1.24 1.26 1.33 1.40 1.49

Depending on where you live you may see the measurements represented in two different ways on the packaging.

In the US string gauge measurements can be a bit confusing for players at first because the number representing the gauge is counterintuitive.

As you can see from the table above the higher the gauge the thinner the string and the lower the gauge the thicker the string.

If you don’t live in the US you’ll typically find string gauge represented in millimeters (mm), however players in the US will also find it helpful to know these measurements as not all manufacturers will list the gauge 19-15 on their packages.

The most common measurements and therefore widest selection of strings that you’ll find available are 17, 16L and 16. While there are certainly strings available outside this range most players tend to fall within this range when stringing their racquets across many different types of string.

Helpful tip: it’s important to note that the above measurements are guidelines, which most manufacturers will follow. However, from time to time you will come across strings sets that are labeled outside of these recommendations, so it can always be helpful to check the package so you know what you’re using.

String Gauge and Performance

Of course, knowing string gauge isn’t all that helpful if you’re not clear on exactly how the thickness of a string impacts performance.

There are two main factors players usually consider when selecting a string gauge: durability and spin potential.

Tennis Gauge Durability & Spin Comparison Graph


Typically the heavier the gauge or thicker the string the more durable and long lasting that string will be. When you play tennis your strings produce friction at the cross-sections where they overlap each other. Over time you’ll notice that your strings cut into each other and begin to notch, so naturally the thicker they are the longer they’ll last.

Thicker strings can also withstand greater impact, which helps extend the life too.

I say “typically” because there are a wide variety of factors that can influence the longevity of a string including: material, construction, tension, string pattern and density, racquet construction, etc…

All else equal, thicker string are more durable and it’s a great rule of thumb to use when evaluating strings.

Spin Potential

Beyond durability players also rely on their string gauge to influence their potential for generating spin. The thinner the string the more potential for spin, while the thicker the less potential for spin.

This is due to the fact that thinner strings can bury themselves deeper into the ball and as a result “grab” the ball, which results in more spin. The thicker the string the lower the ability for string to do so resulting in less potential for spin.

However, just because you have thin strings doesn’t mean you’re going to generate massive spin. It’s one of the many factors that can influence spin, but your grip and technique will have much greater influence over spin.

Which String Gauge Should I Use?

Every player is different and so are their needs and preferences. Recognizing this, it can be helpful to consider the following factors when evaluating string gauge.

Level of Play

If you’re brand new to tennis then I would typically recommend players go with a thicker string. When you’re just getting started you’ll unlikely be able to notice the nuance differences between a higher or lower gauge string. However, you will be likely to appreciate the extra durability of a lower gauge string. Recognizing this I’d recommend 16 for most new players.

If you’re intermediate to advanced then I’d recommend players go thinner and experimenting with different gauges. A great place to start is 17 and then you can move up as you feel comfortable.


If you can’t afford to string your racquet frequently I’d also recommend you string with a lower gauge string to help avoid breakage and increase the longevity or your strings.

Racquet stringing can be expensive especially when you take into consideration the labor to string your racquet. You can go thicker, but 16 will usually do the trick while helping maintain good solid playability and potential for spin.

Frequency of Play

Another factor to consider is frequency of play. If you’re only playing twice a month then you might not be as concerned with longevity so you may be comfortable stringing with a higher gauge.

After all, you’ll still want to replace your strings on a semi-regular basis since strings naturally lose their tension and liveliness over time.

On the other hand, if you’re playing 5 days a week and you can’t afford to restring every week then you might want to use a lower gauge to increase the life of your strings.

How Do You Know What You’re Buying?

String manufacturers always label their strings either with the gauge or by specifying the measurement of the strings.

Here are a few examples of string packages with the gauge of the string highlighted.

Tennis String Gauge Package Examples

Depending on your personal preferences you may choose to use one string gauge or another. As you progress it can be helpful to experiment with different gauge tennis strings especially within the same type of string as performance will vary.

What gauge tennis strings are you using and why? Let us know in the comments below!

Want to learn more about strings? Check out some of our other articles:

Photo Credit: djneight

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