How the calculator works
It uses the most widely quoted sizing rule in kitesurfing: multiply your weight in kilograms by 2.2, then divide by the wind speed in knots. A 75 kg rider in 15 knots gets 75 × 2.2 ÷ 15 = 11, so an 11 m² kite.
The same rule sits roughly in the middle of most manufacturers' size charts for an intermediate freerider on a twin-tip of about 138–142 cm. We round to the nearest whole square metre, because that's how most kites are sold.
For the two-kite quiver, the calculator splits your wind range in half and sizes each kite for the lighter end of its half. You can always depower a kite that's slightly big, but you can't add power to one that's too small.
Where the rule of thumb breaks down
No formula knows your local conditions. Treat the number as the size to ask about, not the size to order.
- Gusty wind. If the gusts are much stronger than the average wind, size for the gusts, or go one size down.
- Board size. A bigger board gets going in less wind, so you can ride a smaller kite. A small board needs more power. See twin-tip vs directional boards.
- Ability. Confident riders squeeze more range out of a kite. If you're still learning, an overpowered kite is harder and riskier to handle than an underpowered one. When in doubt, go smaller.
- Kite type. Big-air and light-wind kites are built for different ends of the range, so their sweet spots won't match a freeride chart exactly.
- Very light or very strong wind. In very light wind, a bigger board or a foil usually helps more than an ever-bigger kite. In very strong wind, the right call is often to stay on the beach.
Building a two-kite quiver
Most riders own two kites that together cover their usual wind: a larger one for the lighter days and a smaller one for the windy ones. Put your own weight and wind range in above to see which two sizes fit you.
If you're buying your first kite, size it for the wind you'll ride most often at your spot, then add the second kite once you know which days you're missing. Our guide to choosing your first kite covers kite types and what to look for, and the kitesurfing safety checklist covers the kit that goes with it.
Unfamiliar terms like depower, low end or wind window are explained in the kitesurfing glossary.