Crosswind Calculator
Enter wind speed, wind direction (where the wind is coming from) and runway heading to instantly compute the crosswind and headwind/tailwind components, converted to knots to check against your limit.
Crosswind = wind speed × sin(α) (positive = wind from right, negative = from left)
Head/Tailwind = wind speed × cos(α) (positive = headwind, negative = tailwind)
Crosswind (kt) = |crosswind| × unit-to-knot factor
Wind speed unit conversion factors (→ knots)
| Unit | Factor to knots | Note |
|---|---|---|
| knots (kt) | 1.000 | aviation standard |
| km/h | 0.53996 | common in meteorology |
| mph | 0.86898 | US ground standard |
| m/s | 1.94384 | scientific standard |
Frequently asked questions
How is the crosswind component calculated?
Take the difference between wind direction and runway heading, normalize it to ±180° to get the relative angle α. The crosswind component is wind speed × sin(α) and the headwind or tailwind component is wind speed × cos(α). A larger angle means more crosswind and less usable headwind; beyond 90° the wind becomes a tailwind component.
Why is the crosswind limit usually given in knots?
Aviation uses knots as the standard wind unit, and aircraft manuals list maximum demonstrated crosswind and gust limits in knots. This tool converts the crosswind to knots so you can directly compare it with your aircraft's limit.
What does "wind from the right" mean?
When the relative angle α is positive, the wind comes from the right side of the runway direction (right crosswind) and pushes the aircraft left; a negative α means a left crosswind. Pilots use this to decide left or right rudder to hold the centerline.