Kite, sail & wing size calculator
Your weight, today's wind, your discipline — the gear size that fits. Kitesurf kites, windsurf sails and wing foil wings, with the closest real sizes you can actually buy.
Closest real size: 11.0 m² (ideal at ~15 kt)
Wind picking up → 10.0 m²
Wind backing off → 12.0 m²
Rule-of-thumb for flat-ish water and steady wind. Gusty spot or waves? Take the smaller size. And remember the number that matters is the gust, not the average — check both.
Kite size chart
Kite size in m² for an intermediate twin-tip rider (kite ≈ 2.2 × kg ÷ kt, the J. Douglass baseline most kite calculators use). Freestyle riders often go one size down; lightwind foilers much smaller.
| Weight | 12 kt | 15 kt | 18 kt | 22 kt | 26 kt | 30 kt |
|---|---|---|---|---|---|---|
| 55 kg | 10.1 | 8.1 | 6.7 | 5.5 | 4.7 | 4.0 |
| 65 kg | 11.9 | 9.5 | 7.9 | 6.5 | 5.5 | 4.8 |
| 75 kg | 13.8 | 11.0 | 9.2 | 7.5 | 6.3 | 5.5 |
| 85 kg | 15.6 | 12.5 | 10.4 | 8.5 | 7.2 | 6.2 |
| 95 kg | 17.4 | 13.9 | 11.6 | 9.5 | 8.0 | 7.0 |
Windsurf sail size chart
Freeride sail size in m² for an intermediate sailor. Wave sailing runs 0.5–1 m² smaller; slalom and early-planing setups bigger. Below ~12 kt you're pumping to plane on any of these.
| Weight | 10 kt | 12 kt | 15 kt | 18 kt | 22 kt | 26 kt |
|---|---|---|---|---|---|---|
| 55 kg | 5.7 | 5.2 | 4.7 | 4.3 | 3.9 | 3.6 |
| 65 kg | 6.8 | 6.2 | 5.5 | 5.1 | 4.6 | 4.2 |
| 75 kg | 7.8 | 7.1 | 6.4 | 5.8 | 5.3 | 4.9 |
| 85 kg | 8.9 | 8.1 | 7.2 | 6.6 | 6.0 | 5.5 |
| 95 kg | 9.9 | 9.0 | 8.1 | 7.4 | 6.7 | 6.1 |
Wing foil size chart
Wing size in m² for an intermediate wing foiler on a floaty board. Add 0.5–1 m² while learning; drop half a size once your pumping is dialled.
| Weight | 12 kt | 15 kt | 18 kt | 22 kt | 26 kt | 30 kt |
|---|---|---|---|---|---|---|
| 55 kg | 4.3 | 3.8 | 3.5 | 3.2 | 2.9 | 2.7 |
| 65 kg | 5.1 | 4.5 | 4.1 | 3.7 | 3.4 | 3.2 |
| 75 kg | 5.8 | 5.2 | 4.8 | 4.3 | 4.0 | 3.7 |
| 85 kg | 6.6 | 5.9 | 5.4 | 4.9 | 4.5 | 4.2 |
| 95 kg | 7.4 | 6.6 | 6.0 | 5.5 | 5.0 | 4.7 |
Common questions
What size kite do I need for 15 knots?
Rule of thumb: kite size = 2.2 × your weight in kg ÷ wind in knots. At 15 knots that's an 11 m² kite for a 75 kg rider, 9 m² at 60 kg, 13 m² at 90 kg — assuming a twin-tip and intermediate level.
What kite size for 70 kg in 20–23 knots?
7.7 m² at 20 knots, 6.7 m² at 23 — an 8 m² at the bottom of that range, a 7 m² at the top. If the window really spans 20 to 23, rig the 7. An underpowered kite still rides as the wind fills in; an overpowered one only gets worse.
What kite do I need for 8 m/s, or 12 mph?
Convert first: 8 m/s is 15.6 knots, 12 mph is 10.4. A 75 kg rider needs 10.6 m² at 15.6 knots — call it an 11 m². At 10.4 knots the same rider needs 15.9 m², a 15 m² light-wind kite rather than an everyday one. The calculator above takes knots, m/s, km/h and mph directly, so you can skip the arithmetic.
How much wind does a 9 m² kite need?
Wind in knots = 2.2 × weight in kg ÷ kite size. A 9 m² is the ideal kite at about 20 knots for an 80 kg rider, 18 knots at 75 kg and 16 at 65 kg. Those are midpoints, not limits: most riders hold a size for a few knots either side before they swap.
What is the best kite size for light wind at 84 kg?
For an intermediate rider the baseline asks for 13.2 m² in 14 knots and 15.4 m² in 12 — a 13.5 and a 15, both sizes brands actually sell. Below about 11 knots it asks for more than the 17 m² at the top of these charts, and the answer becomes a foil board rather than a bigger kite.
Is the calculation the same for gusty conditions?
No — size for the gusts, not the average. If the spot reads 15 gusting 22, rig for something closer to 20. On gusty days take the smaller of two candidate sizes; a slightly underpowered kite is annoying, an overpowered one is dangerous.
Why am I overpowered on a kite foil at 18 knots?
Because every number on this page models a twin-tip. A foil needs far less power to get going and keeps going through the lulls, so foil riders run roughly half to two-thirds of the twin-tip size: where a 75 kg twin-tip rider takes 9.2 m² at 18 knots, the same rider on a foil is usually on 5 to 7. Size down from these charts whenever you are foiling.
Is a 4.2 m² wing right for an 80 kg rider?
At that weight it is a strong-wind wing: 4.2 m² is the ideal size for 80 kg at about 26 knots. For the more usual 15 to 18 knots the same rider wants 5.6 down to 5.1 m². Check the number itself too — 4.2 is a windsurf sail size, while wings are sold in half-metre steps from 2.5 to 7.
What's the minimum wind to kitesurf, windsurf or wing?
About 8 knots for kitesurfing (with your biggest kite), 7–10 knots to start moving on a windsurfer (planing needs 12–15), and 8–10 knots for wing foiling once you can pump onto the foil. Below that it's paddle territory.
Do beginners need bigger or smaller gear?
Kite and sail: smaller — you give up some power for control while learning. Wing: bigger — the extra area helps you get on the foil, so wing charts add 0.5–1 m² for beginners.
The size is only half the answer — the other half is what the wind is doing right now.
WindNow shows live wind speed, gusts and direction from real coastal weather stations across France, Denmark, Croatia and Slovenia — minutes old, not a forecast.
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