Sky DutyFree Crosswind Component Calculator
Enter a runway heading (or runway number), wind direction, and wind speed, and this crosswind calculator returns the crosswind component, the headwind or tailwind, and the wind angle to the runway. No download, no account.
What the crosswind component is
Wind rarely blows straight down the runway. When it comes in at an angle, it splits into two parts: the part along the runway, which is a headwind or a tailwind, and the part across the runway, which is the crosswind component. The crosswind component is the number that matters for directional control on takeoff and landing, and it is what you compare against your aircraft's maximum demonstrated crosswind. Because it depends on the angle between the wind and the runway, a strong wind nearly aligned with the runway can be easier to handle than a moderate wind blowing across it.
The crosswind formula
Both components come from the angle between the wind direction and the runway heading:
- Crosswind = wind speed × sin(angle) — the component across the runway, labeled left or right depending on which side the wind is from.
- Headwind = wind speed × cos(angle) — the component along the runway. A negative result means a tailwind.
The angle is the difference between the wind direction and the runway heading. This calculator wraps that difference correctly around 360 degrees, so it works whether the runway is 09, 27, or 36 and whichever side the wind sits on. Enter the runway as a heading in degrees or as a runway number, which is simply the heading divided by ten.
Plan for gusts
Run the crosswind for the gust, not just the steady wind. If the ATIS or METAR reports wind as 030 at 15 gusting 25, compute the crosswind at 25 knots so you are planning for the worst case you may see in the flare. Compare that number against your aircraft's maximum demonstrated crosswind component and your own personal limits. The maximum demonstrated value is not a regulatory limit, but exceeding it means you are operating beyond what was shown to be controllable during certification — a good reason to pick a different runway or divert.
Worked example
Landing on runway 36 (heading 360 degrees) with the wind reported from 030 at 20 knots, the wind angle to the runway is 30 degrees, and the wind is from the right. The crosswind component is 20 × sin(30°) = 20 × 0.5 = 10 knots from the right. The headwind component is 20 × cos(30°) = 20 × 0.866 ≈ 17.3 knots. So you would plan for a 10-knot right crosswind and about 17 knots of headwind on that runway.
The same tools, offline in the cockpit
Wind-triangle math like this is part of the E6B built into the Sky Duty iOS app, alongside scheduling, logbook, maintenance, and expense tracking. All of it works offline, so you can run the numbers at a remote strip with no signal. Sky Duty is not an electronic flight bag; always confirm crosswind limits against your aircraft POH.
Frequently Asked Questions
How do you calculate the crosswind component?
What is the difference between the crosswind and headwind components?
How do I use a runway number for the crosswind calculation?
Should I calculate crosswind for wind gusts?
What is a maximum demonstrated crosswind component?
Get the full E6B in Sky Duty
Crosswind, wind correction, density altitude, and fuel — plus scheduling, logbook, maintenance, and expenses. All in one offline-first iOS app.
