True-Wind Calculator

The wind you feel isn't the real wind.

Turn apparent wind into true wind in two taps — no wind instruments required. Built by a sailor, used since 2013.

Privacy → What we collect: nothing. Here's the detail. Support → Questions, the formula, Pro and restoring purchases.

About the app

Enter boat speed, apparent wind speed, apparent wind angle and heading. The app does exact vector math — no lookup tables, no approximations — and gives you true wind speed and direction instantly. Boat speed and heading fill from GPS and compass with one tap. Works completely offline.

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