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Free tools

Wind tools that do the math for you.

Convert wind speeds, size your kite or wing, and check if today is worth the drive — free, in your browser, no signup. Built by the team behind the free WindUp live wind alarm.

Pick a tool

Three calculators every wind rider ends up needing.

Wind speed converter

Knots ⇄ mph ⇄ km/h ⇄ m/s with the Beaufort force alongside. The unit-soup fixer for forecasts, spot guides and gear charts.

Kite size calculator

Your weight + today's wind = the kite to pump. Twin-tip, surfboard and foil modes, with a gusty-day recommendation.

Wing size calculator

Wing foil sizing by weight, wind and level — from first taxi runs to pumping onto foil in 12 knots.
Try one now

Is it windy enough for your sport today?

Pick your sport, drag to today's forecast, and get a straight answer.

Numbers from a forecast are a promise, not a fact. When you want the real thing, the WindUp app watches live stations and rings the moment your spot actually turns on — a free alarm, iOS and Android.

Questions

Free tools FAQ

Are the WindUp wind tools really free?
Yes — every tool on this page runs free in your browser with no signup, no account and no paywall. They're built by the WindUp team, the same people who make the free live wind alarm, and they stay free for the same reason: riders shouldn't pay to know the wind.
How accurate are the kite and wing size calculators?
They use the same rule-of-thumb formulas instructors teach — rider weight times a constant, divided by wind speed in knots, adjusted for board or level. That gets you within one size for typical conditions. Brand design, gusts and water state shift the answer, so treat it as your starting size.
Do these tools work on my phone?
Yes. Every tool is a lightweight web widget that runs offline-fast on any modern phone, tablet or desktop browser — no app install needed. If you want the wind to come to you instead, WindUp rings a free alarm the moment your spot crosses your threshold.

Done calculating? Stop forecasting, start riding.

WindUp rings a real, free alarm — even on silent — the second live wind at your spot crosses your number.

Download on the App Store Get it onGoogle Play

Free live alarm · iOS & Android · Rings on Silent & DND