Kite size calculator by weight and wind

The calculator uses 2.2 × weight (kg) ÷ wind (knots) as a sizing estimate, with adjustments for board type. This is a heuristic, not a physical derivation or a manufacturer’s wind-range chart. Kite design, rider skill, gusts and water conditions can change the appropriate size.

Board choice shifts the answer. A surfboard's extra float lets you shave roughly 10% off; a hydrofoil's near-zero drag cuts kite size by close to 40% — which is why foilers ride 6 m kites on days twin-tippers rig 9s. And the calculator's gusty-day advice isn't hedging: because pull rises with wind squared, rigging for the lulls means every gust hits you with interest. Full threshold guidance is in how much wind you need to kitesurf and the wind speed chart.

One honest caveat: no formula sees your local spot. Current, chop, water state and kite design all nudge the real answer — Tarifa's gusty Levante rides a size smaller than the same reading somewhere steady. Sanity-check against your brand's chart, and when in doubt between two kites in gusty wind, take the small one. Thinking in mph instead? Run it through the wind speed converter first.