Windsurfing Wind Calculator
Estimate the sail size that suits the wind speed, your body weight, and your skill level before you rig up.
How sail size is estimated
Windsurfers size their sail to match wind strength and their own body weight: more wind or a lighter rider means a smaller sail, while lighter wind or a heavier rider means a bigger sail. This calculator uses a widely referenced rule of thumb from windsurfing sail-size charts: Sail area (m²) ≈ 1.2 × body weight (kg) ÷ wind speed (knots), adjusted slightly for skill level since beginners generally need a bit more power to plane and advanced sailors can drive a smaller sail harder.
How to use it
Enter your body weight, the true wind speed you’re expecting (in knots), and your skill level. The calculator returns a recommended sail size plus a practical range, since conditions, board choice, and personal preference all shift the ideal size somewhat.
This is a general starting-point estimate for planning your gear bag, not a substitute for local knowledge, gusty or shifting wind conditions, or advice from your local windsurfing shop.