Crosswind Component Calculator
Enter the runway and the wind, and get the headwind and crosswind components at a glance. The same math you run in preflight and the examiner asks you to do on the ground.
Wind is 300° at 15 kt, 30° off runway 27 (270°). Compare the crosswind against your aircraft's maximum demonstrated crosswind before you commit to the approach.
The math behind it
The angle (theta) is the difference between the wind direction and the runway heading. From there it is basic trigonometry:
In the cockpit you use the FAA “clock method” to estimate the crosswind fraction from the angle, no calculator required:
| Wind angle | Crosswind is about |
|---|---|
| 30° | 50% of the wind speed |
| 45° | 70% of the wind speed |
| 60° | 85% of the wind speed |
| 90° | 100% of the wind speed |
How to read it
Wind rarely blows straight down the runway. The part blowing along the runway is your headwind (or tailwind); the part blowing across it is the crosswind that pushes you toward the edge. The bigger the angle between the wind and the runway, the more of the wind becomes crosswind. At 90 degrees it is all crosswind; at 30 degrees, roughly half.
On the written and the checkride you are expected to estimate this quickly, and in the airplane you compare the crosswind against your aircraft's maximum demonstrated crosswind before committing to the approach.