The question “What string tension should I use?” is a good question, and probably more important than most realise. The short answer is to use the tension that you like and prefer, but finding your preference can be complicated. A good starting point is to ask your stringer. They can make a suggestion based on their experience.

The string tension is only one of several things, that impacts your experience of the strings in your racquet. The list includes static tension, dynamic tension, tension maintenance, string pattern, string stiffness, string material, technique and playing style, your physique etc. But rather than go through them all, I’ll introduce them as we go.

The starting point

Most club players should stay within the range of 45 – 55 pounds or 20 – 25 kg range. For most racquets, I’d start in the middle with 50 pounds / 22.5 kg. Unless you are sure, don’t go above 53 pounds, as it starts to become elbow injury territory.

Open vs tight string patterns

50 pounds in a racquet with an open string pattern will feel softer (looser) than 50 pounds in a racquet with a tight string pattern. Racquets with a 16×19 and 100 square inch head sizes are generally considered open. Prince offers several racquets with 16×18 string patterns. The Wilson Ultra Pro 99 (2025) also comes with a 16×18 string pattern. 18×20 is considered a tight string pattern, whereas the 18×19 or 16×20 are somewhere in between.

An open string patterns will feel softer because there is more space between the strings. More space equals less string to resist the ball on impact causing the strings to move more. More movement creates a softer feeling.

So depending on the string pattern of your racquet, you might want to go a couple pounds up or down. For example, 45 pounds for an 18×20, 98 square inch head size racquet will feel as stiff as 50 pounds for a 16×19, 100 square inch head size racquet.

String stiffness

You can look up the string stiffness in the Tennis Warehouse University string database.

• Soft synthetic gut or multifilament strings (175 stiffness or less) are great for added power and comfort, but I’d be weary of asking the stringer to string them tighter unless they are very experienced. The inexperienced stringer will keep pulling the string until it holds the requested tension. But because it is soft, it will just stretch out completely and have no flex left. This will create a surprisingly stiff feeling and likely stiffer than if you had used a stiffer poly string.
• Medium stiff poly strings (190 to 210 stiffness range) provides a good combination of comfort, power and control. They can play well in the 50-52 pound range, but most newer strings released retain a good level of control even in the 45-50 pound range.
• Stiff poly strings (220 and above) should come with a tennis elbow warning, unless you string them very low – e.g., 45 pounds or lower. Obviously, “feel” is a personal thing, and you might be ok, but, as a general rule, be warned.

Tension maintenance

Poly strings generally need to be replaced before they break, unless you hit very hard or play with an extreme open string pattern (e.g., Prince RipStick). Two things start to happen:

1. Loss of elasticity – the string becomes stiffer and can cause the string bed to become board like. You loose power and spin, as well as increasing the chance of elbow injury.
2. Loss of tension – the string stretches out and becomes longer. If the string retains some of its elasticity, then you have a trampoline with plenty of power but no control.

Stringers and tension accuracy

Different stringers will not produce the same tension per stringing job for the same racquet, same string, and the same tension. If you change stringer, then you’ll need to gage how close their 50 pounds is your previous stringer’s 50 pounds.

Also check if they do strange stuff like pre-stretch of poly strings. Hint: pre-stretching is only done by the manufacturer if they designed that way, or for natural gut strings. Your stringer should not be pre-stretching poly strings. It will only reduce the life span of the string (see previous section).

Tools

You can purchase the Tourna Stringmeter to keep track of the tension – it’s about $70 from Amazon or TennisOnly. But keep in mind, it is basically just a spring inside a plastic casing, so don’t read too much into the absolute values. It is best as a relative measurement.

In summary

Your tension is your personal tension. But do try different tensions. And do try the lower ranges – I have been as low as 42 pounds or 19 kg. There is no right or wrong despite what some stringers will tell you. Sinner uses 60 pounds and Mannarino is low 30 pounds, because it is a personal thing.

My current tension choice is 46 pounds. I use the HEAD Lynx Tour (mains) and HEAD Lynx Touch (cross) strings in my HEAD Prestige MP 2021.