Updated November 2026 · free, works in your browser
Formula
Wind angle α = wind direction − runway heading (normalised to −180°…180°).
Crosswind = wind speed × sin(α)
Headwind = wind speed × cos(α); a negative value is a tailwind.
The crosswind component is the part of the wind that blows across a runway, and the headwind component is the part that blows along it. Enter the runway heading, the wind direction and the wind speed above, and the calculator shows both values at once, plus whether the wind comes from the left or the right and whether you have a headwind or a tailwind.
How to use
- Enter the runway heading in degrees. A runway number is the heading divided by ten, so runway 15 is 150° and runway 33 is 330°.
- Enter the wind direction in degrees, which is the direction the wind blows from, as given in an airport weather report or by air traffic control.
- Enter the wind speed and choose the unit: knots, mph, km/h or m/s.
- Optionally, enter a gust speed to see the crosswind at the strongest gusts.
- Read the crosswind and headwind (or tailwind) values. In the full version you can copy a link that restores your inputs.
How it is calculated
The calculator uses basic trigonometry. First it finds the wind angle, which is the wind direction minus the runway heading, normalised to a value between −180° and 180°. Then:
- Crosswind = wind speed × sin(wind angle)
- Headwind = wind speed × cos(wind angle)
A positive crosswind means the wind comes from the right of the runway direction, a negative one from the left. A negative headwind value is shown as a tailwind. The results are in the same unit as the wind speed and are rounded to one decimal place. This is the standard wind-triangle resolution taught in pilot training.
Quick reference by wind angle
| Angle off the runway | Crosswind share of wind speed | Headwind share of wind speed |
|---|---|---|
| 10° | 0.17 | 0.98 |
| 20° | 0.34 | 0.94 |
| 30° | 0.50 | 0.87 |
| 40° | 0.64 | 0.77 |
| 45° | 0.71 | 0.71 |
| 50° | 0.77 | 0.64 |
| 60° | 0.87 | 0.50 |
| 90° | 1.00 | 0.00 |
Frequently asked questions
Which crosswind is too strong to land in?
It depends on the aircraft, the runway and the pilot. Many flight manuals list a demonstrated or maximum crosswind value for the type. Always follow the limits in your aircraft's manual and your own personal minimums.
Is the wind direction magnetic or true?
Wind given by air traffic control or an automated airport information broadcast is normally magnetic, matching runway headings. Wind in a METAR or TAF is given as true. If you use those reports, convert for local magnetic variation first.
What does a negative headwind mean?
It is a tailwind. When the wind comes from behind the aircraft, the cosine of the wind angle is negative, so the calculator labels the value as a tailwind component.
Should I use the gust speed?
Many pilots check the crosswind for the gust value as well as the steady wind, because gusts are what push the crosswind component highest. The optional gust field does this with the same wind angle.
How do I find the runway heading?
Take the runway number and add a zero. Runway 04 is about 040°, and its opposite end, runway 22, is about 220°. The exact magnetic heading is printed in airport charts.
This tool gives a calculation only. It does not replace the official weather report, the aircraft manual or the pilot's own judgement.
Wind has a way of changing travel plans. If you fly yourself, or just wait for a flight, a diversion or a delay can leave you stranded overnight. It helps to check ahead for places to stay near the airport and to know the cancellation terms, so a weather change does not turn into a scramble for a bed.
Other tools
- Density Altitude CalculatorEnter field elevation, temperature and altimeter setting to get pressure altitude and density altitude.
- Wind Correction and Groundspeed CalculatorEnter course, true airspeed and wind to get the wind correction angle, heading to fly and groundspeed (the E6B wind problem).
- Airport Runway Length CheckerSearch a Vermont airport and see its longest runway, surface type and whether your required distance fits.
This is an independent guide. It is not affiliated with Vermont Agency of Transportation.