The number printed on a tennis string package can change how a racket feels, but it is easy to read it the wrong way: a higher gauge number usually means a thinner string. That small difference in diameter can affect spin, feel, durability, and how often you need to restring.
Here’s how tennis string gauge works, how to choose one for your playing style, and what to try if you’re deciding between popular string options. Gauge is only one part of the setup, though—string material, racket pattern, tension, and your own swing all matter too.
What Does Tennis String Gauge Mean?
String gauge is the string’s thickness, usually measured in millimeters. In the common numbering system, the higher the gauge number, the thinner the string. So a 17-gauge string is generally thinner than a 16-gauge string.
Gauge labels are not perfectly standardized. A 16-gauge string from one brand may measure slightly differently from another brand’s 16. Check the manufacturer’s diameter when comparing specific strings.
| Common label | Approximate diameter | General description |
|---|---|---|
| 15 | 1.41–1.49 mm | Thick |
| 16 | 1.26–1.34 mm | Medium-thick |
| 16L | About 1.25–1.30 mm | Between 16 and 17 |
| 17 | 1.20–1.24 mm | Thin |
| 18 | 1.10–1.16 mm | Very thin |
The “L” stands for “light” and usually indicates a size between two standard gauges. Always use the maker’s listed diameter as the more useful comparison.
How Gauge Changes the Way a Racket Plays
Thinner strings: more feel, less lifespan
A thinner string can feel lively and responsive. It may also let the string bed move more freely, which can help some players produce spin. But a thin string has less material to wear through, so it often breaks sooner—especially for players who hit hard with heavy topspin.
Thin strings aren’t an automatic upgrade for control or spin. The string’s material and shape, the racket’s pattern, and how you swing all affect the result. Think of gauge as one adjustment, not a shortcut to a different game.
Thicker strings: extra durability
A thicker string often lasts longer and can feel a little firmer or more muted. That can suit a frequent string-breaker who wants fewer restringing trips. The trade-off is that the response may feel less crisp than the same model in a thinner gauge.
Neither choice is always more powerful or more comfortable. A soft multifilament in a thicker gauge may feel easier on the arm than a stiff polyester in a thin gauge. If comfort is your main concern, pay close attention to string material and tension—not just diameter.
How to Choose a Tennis String Gauge
- If you break strings often: Start with 16 or 16L, or consider a more durable string material. A thicker gauge may help, but a durable string can make a bigger difference.
- If you rarely break strings: Try 17 gauge for a livelier feel, or test 16 against 17 in the same string model.
- If you want more comfort: Look at multifilament or natural gut options and consider asking a stringer about lower tension. Gauge alone cannot make a stiff string arm-friendly.
- If you use polyester: Don’t choose a thin poly just to chase spin. Poly can feel firm, and it should be replaced when it goes dead even if it has not snapped.
- If your racket has an open string pattern: The strings may move and wear faster, so a thicker gauge can be worth testing.
For a useful comparison, change only the gauge while keeping the string model, racket, and tension the same. Try each setup for a few hitting sessions and note comfort, launch, spin, and how quickly the strings fray or lose playability.
Five String Options to Try in Different Gauges
These are examples of familiar string models that come in multiple gauges or gauge variants. Check the current manufacturer’s listings before ordering, since size options can differ by model and region.
| String | Gauge to consider | What to expect | Potential drawback |
|---|---|---|---|
| Solinco Hyper-G | 17 for a thinner test; 16L for a more durable one | Shaped polyester aimed at players who take full swings and want a controlled, spin-friendly response. | Like other polyester strings, it may feel firm. It is not the first choice for every arm or every playing level. |
| Babolat RPM Blast | 17 for a livelier feel; 16 for added wear resistance | A shaped polyester option often chosen by aggressive baseliners who want a firm, controlled string bed. | Can feel stiff, and the thinner size may wear faster for heavy hitters. |
| Wilson NXT | 17 for touch; 16 for a little more durability | A multifilament designed for a softer, more comfortable response than typical polyester. | It generally won’t last as long as a durable polyester for players who break strings frequently. |
| Tecnifibre X-One Biphase | 17 for feel; 16 for a sturdier trial | A lively multifilament suited to players who value comfort, power, and touch. | Its lively response may take adjustment if you prefer a firm, low-powered setup. |
| HEAD Hawk Touch | 17 for a thinner feel; 16 for a thicker option | A control-focused polyester to consider if you already like the firmer response of poly. | It may not suit players seeking a soft string bed or those with arm discomfort. |
These are starting points, not universal prescriptions. A 17-gauge multifilament and a 17-gauge polyester can feel very different because their materials and construction differ. If you’re unsure, ask your stringer to recommend a setup based on your racket, how often you break strings, and any comfort concerns.
When Should You Change Gauge?
Consider moving thicker if you regularly snap strings, especially in the same spot, or if a thin setup feels too lively. Try thinner if your strings last a long time and you want to explore a more responsive feel. If the racket feels uncomfortable, don’t assume a thinner gauge will solve it; discuss string type and tension first.
Also check your racket’s recommended tension range and follow your stringer’s advice. A change in gauge can slightly alter the way the string bed responds, so a familiar tension may not feel exactly the same in a different thickness.
Frequently Asked Questions
Is 16 or 17 gauge thinner?
17 gauge is generally thinner than 16 gauge. A thinner string may feel more responsive, but it often wears through sooner.
Does a thinner tennis string give more spin?
It can help some players, but spin depends on the full setup: string shape and material, racket pattern, tension, and swing technique. Gauge by itself does not guarantee more spin.
Which gauge is best for beginners?
There is no single best gauge. Many beginners do well with a 16-gauge synthetic gut or multifilament because it offers a practical balance of feel and durability. Comfort and budget matter as much as the number.
Should I use a thicker string if I keep breaking strings?
It is a reasonable first test, particularly if you currently use a thin gauge. A more durable string material may help too. If you break strings very quickly, ask a stringer to inspect where they break and review your racket pattern and setup.
Final Thoughts
Tennis string gauge is a simple way to fine-tune your racket: higher numbers usually mean thinner strings, while thicker strings often offer more durability. Start with your main need—feel, comfort, or string life—and test one change at a time. The right gauge is the one that suits your swing and holds up without making your racket uncomfortable.
