Crosswind component calculator

Split the reported wind into the part down the runway and the part across it.

How it works

Crosswind = wind speed × sin(angle between wind and runway). Headwind = wind speed × cos(angle). A tailwind simply comes out negative.

The clock rule

For mental arithmetic: at 30° the crosswind is half the wind speed, at 45° about 70%, at 60° about 90%, and at 90° all of it. Treat the angle as minutes on a clock face and read the fraction off — 15 minutes is a quarter, 30 is a half.

Use the gust, not the mean

Plan against the gust value, because that is the wind you will be holding aileron into during the flare. Enter it above and both components are shown for it.

Two things that catch people

Tower and ATIS winds are magnetic; the wind in a METAR or a forecast is true. Mixing them costs you the local magnetic variation, which is over 20° in parts of the western United States. And a demonstrated crosswind component in the POH is a value a test pilot achieved on a dry runway — not a limit, and not a promise about you on a wet one.

Live: the strongest gusts being reported right now

Parsed from the gust group in each raw report. Run one of these through the calculator above with a plausible runway heading to see what it would actually mean on final.

Other calculators

For planning and study, not for operational use. Aircraft performance comes from your POH, not from a generic formula.