The string matters more than the racquet, and the tension matters more than the brand of string. This guide is built on one thing: the tension model our Master Stringer publishes and signs on our own string tension calculator. Same numbers, written out, so you can see the reasoning instead of just the answer.
Tennis ProSport, 2330 chemin Ste-Foy, local 102, Québec City. Stringing done in the shop since 1996.
Start from one number: 53 lb
Our 2026 reference is 53 lb (24.0 kg): a monofilament, in a 100 sq in frame, for a player who wants a balance of control and power. Everything else in this guide is an adjustment to that one number.
It is deliberately higher than most frames suggest. Look at the tension ranges printed on the frames we actually sell, all of them 100 sq in: our product pages record 44–53 lb for the Babolat Pure Aero Team and Lite Gen 9, 47–57 lb for the Wilson Defyer 100, 48–57 lb across the HEAD Boom, Speed, Gravity and Extreme lines, and 50–60 lb for the Völkl V-Cell 6 and Vöstra V5 and V7.
Same head size, four brands, 16 lb of disagreement. Those ranges were set at different times with different strings in mind. They are a legal envelope, not a recommendation. Start from 53 and adjust.
Adjustment 1 — your head size
A bigger string bed has longer strings, and longer strings stretch more at the same tension. So a bigger head goes up, a smaller head goes down. Monofilament, balance of control and power:
| Head size | Adjustment | Tension to ask for | In kg |
|---|---|---|---|
| 95 sq in | −3 lb | 49–51 lb | 22.2–23.1 kg |
| 97–98 sq in | −2 lb | 50–52 lb | 22.7–23.6 kg |
| 100 sq in | reference | 52–54 lb | 23.6–24.5 kg |
| 105–107 sq in | +2 lb | 54–56 lb | 24.5–25.4 kg |
| 111 sq in | +3 lb | 55–57 lb | 24.9–25.9 kg |
| 115 sq in | +4 lb | 56–58 lb | 25.4–26.3 kg |
Your head size is stamped on the frame, and it is in the specifications on every racquet page we publish.
Adjustment 2 — why multifilament goes UP, not down
This is the question we are asked most often at the counter, and almost everyone guesses backwards. Multifilament is roughly 30 % more elastic than monofilament. String it at the same number as a polyester and it will sit softer, launch longer and feel mushy. So it goes up.
| What you are stringing with | Adjustment | In a 100 sq in frame |
|---|---|---|
| Monofilament (polyester, co-poly) | reference | 52–54 lb |
| Synthetic gut | +2 lb | 54–56 lb |
| Multifilament | +3 lb | 55–57 lb |
| Natural gut | +3 lb | 55–57 lb |
| Hybrid (mono mains, multi crosses) | mono at reference, multi +2 lb over it | 53 lb mono / 55 lb multi |
A hybrid is two different strings in the same frame, so it takes two different numbers. In our model the multifilament side carries 2 lb more than the monofilament side — for the same reason as above. If a stringer puts both at one number, the softer string is under-tensioned by about 2 lb and you will feel it on the cross strings.
Adjustment 3 — what you are trying to fix
Two symptoms, two directions:
- The ball flies long on me — you want control. +2 lb.
- I have to force for depth — you want power. −2 lb.
- Neither, or both — stay at the reference.
Our model caps the result at 40 lb at the bottom and 64 lb at the top. If your arithmetic takes you outside that, something in the chain is wrong and it is worth a conversation rather than a machine setting.
Your level does not change the number
Worth saying plainly, because it surprises people: in our model, your level changes which string we suggest, not the tension. Beginner and intermediate players get pointed toward a multifilament or a hybrid rather than a full bed of polyester — more comfort, more forgiveness, better feel for the ball. The tension still comes from head size, string type and what you are trying to fix.
Three worked examples
1. 100 sq in, polyester, the ball keeps flying long.
53 reference + 0 for the head + 0 for the string + 2 for control = 55. Ask for 54–56 lb.
2. 98 sq in, multifilament, no particular complaint.
53 − 2 for the head + 3 for the multifilament + 0 = 54. Ask for 53–55 lb — higher than the polyester number in a bigger frame, which is exactly the point.
3. 107 sq in, synthetic gut, struggling for depth.
53 + 2 for the head + 2 for the synthetic gut − 2 for power = 55. Ask for 54–56 lb.
Then the rule that matters more than the arithmetic: start in the middle of the range. If the ball flies long, go up 2 lb next time. If you have to force for depth, come down 2 lb. Two or three jobs and you will know your own number, and we will keep it on file.
Gauge: the second number on the packet
Gauge is thickness, and the scale runs backwards: the higher the gauge number, the thinner the string. Thinner is softer on the arm and bites the ball more. It also breaks sooner. One family in our catalogue runs the full ladder, which makes the conversion easy to check:
| Gauge | Diameter | On our shelf |
|---|---|---|
| 16g | 1.30 mm | HEAD Hawk Touch 16g |
| 17g | 1.25 mm | HEAD Hawk Touch 17g |
| 18g | 1.20 mm | HEAD Hawk Touch 18g |
| 19g | 1.15 mm | HEAD Hawk Touch 19g |
Our suggestion for most players is 17g. It is the gauge that gives up the least on either side. Go to 18g if your arm is the problem and you do not break strings; stay at 16g if you break a set every two weeks.
How often should you re-string?
Not « when it breaks ». Our model is explicit about monofilament: it loses tension quickly, and it plays at its best for the first 10 to 15 hours. That is a playing-time window, not a calendar.
- 2 hours a week → every 5 to 7 weeks
- 3 hours a week → every 3 to 5 weeks
- 5 hours a week → every 2 to 3 weeks
That is simple division on our own 10-to-15-hour figure, nothing more. A polyester that has not broken in six months has not been fine all along — it has been dead for most of them, and a dead polyester is harder on your elbow than a fresh one.
If your arm, wrist, elbow or shoulder hurts
Then read this sentence twice, because it is the one piece of advice on this page that outranks every number: for a sensitive arm, the string matters more than the tension. Moving to a multifilament, or to a hybrid with a multifilament, does more for your elbow than any adjustment to the machine.
If you will only play polyester, take the softest one we stock: Solinco Confidential Soft. It is on our Master Stringer's Selections page in both 16G and 16L, and it is there for this reason and no other.
The five families, and what we carry in each
Named below only where our own product page states the construction. If a page does not say what a string is made of, we are not going to tell you on this one.
- Monofilament / polyester — the control-and-spin family, and what most competitive players use. Ours include Solinco Tour Bite and Babolat RPM Blast. Browse Solinco, Luxilon and Babolat.
- Multifilament — comfort and power, and the first thing we change for a sore arm. Babolat Xcel, HEAD Velocity MLT, HEAD RIP Control, Tecnifibre X-ONE Biphase.
- Synthetic gut — the honest default for a club racquet. HEAD Synthetic Gut PPS, and Babolat Synthetic Gut on the Babolat page.
- Natural gut — the most elastic of the five, usually used as the mains of a hybrid. Luxilon Natural Gut.
- Hybrid — two strings, two tensions. Our Babolat range includes factory sets that pair the two sides for you, listed as Hybrid RPM Blast 17g + VS 16g and Hybrid RPM Power 17g + Xcel 16g. Or we will build one from any two sets you like.
The whole range is on the tennis strings page, sorted by brand.
Have it strung in Québec City
The calculator gives you a number in about twenty seconds: six questions, one answer. Bring the racquet in and we will fine-tune from there, and keep your tension on file so the next job matches the last one. A racquet bought here is strung for you at the tension you choose, at no extra charge. Our stringing service page has the rest.
Tennis ProSport
2330 chemin Ste-Foy, local 102, Québec QC G1V 1S5
418 380-0775 · info@tennisprosport.com
Open seven days a week. Monday to Wednesday 10 a.m.–5 p.m., Thursday and Friday 10 a.m.–6 p.m., Saturday and Sunday 10 a.m.–5 p.m. Players come to us from Sainte-Foy, Cap-Rouge, Lévis and across the region.
Short answers
What tension should I ask for?
53 lb if you have a 100 sq in frame and a polyester, then adjust: head size, string type, and whether the ball flies long or falls short.
Why would multifilament be strung higher than polyester?
Because it is about 30 % more elastic. At the same number it sits softer. +3 lb puts it back where you expect it.
Should I just use the range printed on my frame?
It is a legal envelope. On 100 sq in frames in our own catalogue those printed ranges differ by 16 lb from brand to brand.
What gauge?
17g (1.25 mm) for most players. 18g if comfort is the priority, 16g if you break strings.
How often?
A monofilament plays at its best for 10 to 15 hours. Divide by your hours a week.
My elbow hurts. Lower the tension?
Change the string first. A multifilament, or a hybrid with a multifilament, does more than any number.