Crosswind Calculator
Wind direction and speed versus your runway → exact crosswind and headwind components, from manual entry or the live METAR at any airport. Know it before you line up.
How crosswind components are calculated
The wind's angle to the runway splits it into two parts: the headwind component (along the runway) and the crosswind component (across it). With the angle between wind and runway heading:
- Crosswind = wind speed × sin(angle)
- Headwind = wind speed × cos(angle), negative means a tailwind
Worked example
Wind 210° at 20 kt, landing runway 24 (heading 240°). The wind is 30° off the runway centerline, so:
- Crosswind = 20 × sin(30°) = 10 kt
- Headwind = 20 × cos(30°) = 17 kt
Enter your runway number (e.g. 24) and the tool uses its heading (240°). Compare the crosswind result against your aircraft's maximum demonstrated crosswind and your own personal minimums.
The clock method, for when you have no calculator
Picture the angle between the wind and the runway as minutes on a clock. 15° is a quarter past, so take a quarter of the wind speed. 30° is half past, half the wind. 45° is three quarters. Anything 60° or more, count the whole wind as crosswind. It is conservative at the large angles and close enough at the small ones: the exact value at 30° is 0.50, at 45° it is 0.71, at 60° it is 0.87. Runway 24 with wind 210° at 20 kt is "half past", 10 kt, the same answer as above.
Gusts
A METAR of 21015G25KT is two winds. The steady 15 kt gives the crosswind you will
trim for on final; the 25 kt gust gives the crosswind that can arrive in the flare, and it is
the one to hold against your limit. In the example above the gust crosswind on runway 24 is
12.5 kt. The common technique adds half the gust factor to approach speed: with a 10 kt spread,
fly 5 kt faster. Enter the gust speed as the wind speed to see the worst case.
True versus magnetic
Runway numbers are magnetic. A written METAR or TAF gives wind in degrees true, so
21015KT in the text is not necessarily 210° on the compass. Tower, ATIS and AWOS
voice reports are already magnetic. In most of the US the variation is under 15°, which shifts
a 30° crosswind angle by half a clock position, but in the Pacific Northwest and New England it
reaches 15° to 20° and matters. The live mode on this page sidesteps it by working entirely in
degrees true: the METAR wind against each runway's true heading. In manual mode, enter the
magnetic direction you would hear from the tower against the runway number.
Tailwind
A negative headwind is a tailwind, and it costs more than the number suggests: landing distance grows about 10% for every 2 kt of tailwind in a typical light single, so a 10 kt tailwind can add half again to the ground roll. Most POHs limit tailwind to 10 kt for published performance. If the tool shows a tailwind on your chosen runway, look at the reciprocal; every airport page shows which runway end the current wind favors.
What is a reasonable crosswind limit?
The POH "maximum demonstrated crosswind" is the strongest crosswind the manufacturer's test pilot landed in during certification, with no special skill required. It is typically 15 kt for a Cessna 172 and 17 kt for a Piper Archer. It is not a limitation, but a student pilot is usually restricted to something well below it by their instructor, and a rusty pilot should be too. The personal minimums tool keeps your own number, and the explainer covers how to set it.
Related
Winds aloft, rather than surface wind, decide your heading and ground speed en route: the E6B flight computer solves that wind triangle. To check the wind at a specific field right now, the live mode here or the field's SkyReady airport page both read the current METAR.
FAQ
Is the maximum demonstrated crosswind a limit?
For most light aircraft it's not a regulatory limit, but it's the most that was demonstrated during certification, a strong reference point. Your personal minimum should usually be at or below it.
Do I use the steady wind or the gust for the crosswind component?
Compute both. The steady value is what you will hold on final; the gust value is what can hit you in the flare. Most pilots compare the gust crosswind against their limit, and add half the gust factor to approach speed.
Is METAR wind true or magnetic?
A METAR or TAF reports wind in degrees true. Tower, ATIS and AWOS voice broadcasts give it in magnetic, which is what runway numbers use. The difference is the local variation, up to about 20 degrees in parts of the US, so a written METAR wind should be corrected before comparing it with a runway number. The live mode on this page avoids the problem by comparing the METAR wind with each runway's true heading.
Can it use live wind for a specific airport?
Yes. Switch to "Live airport wind", enter the ICAO code, and the tool loads the current METAR wind and the airport's real runways, then shows the components for every runway end. You can also open it directly with /tools/crosswind?icao=KLVK.
What is a quick mental crosswind estimate?
The clock method: treat the angle between wind and runway as minutes on a clock face. 15° off is a quarter of the wind, 30° is half, 45° is three quarters, and 60° or more is all of it. Wind 20 kt at 30° off the runway is roughly 10 kt of crosswind; the exact figure is also 10 kt.
Every runway on your route, live
The SkyReady app runs this same crosswind math live across every airport on your route from the current wind — part of a one-tap Go/No-Go readiness brief.