Wind Correction Angle Calculator
Enter your true course, true airspeed, wind direction, and wind speed to get the wind correction angle you need to crab into the wind, the true heading to fly, your resulting ground speed, headwind or tailwind component, crosswind component, and an estimated time of arrival if you add the leg distance. The calculation uses the exact law-of-sines wind triangle, the same math an E6B flight computer does mechanically.
What is the wind correction angle?
The wind correction angle (WCA) is the number of degrees you point the aircraft nose away from your desired track so that the actual flight path, after wind drift is applied, coincides with the desired ground track. Imagine walking in a crosswind: you lean into the wind to go straight. An aircraft does the same by yawing its nose into the wind by the WCA while continuing to move along the intended course. The larger the crosswind relative to airspeed, the larger the correction angle needed. At very high wind-to-airspeed ratios there is no solution, because the wind is stronger than the aircraft can overcome at any heading.
How the wind triangle works
Aviation wind problems are solved with a vector triangle made up of three sides: true airspeed (TAS) along the true heading, wind speed along the wind direction, and ground speed along the true course. The law of sines relates the angles of this triangle. For WCA, the formula is sin(WCA) = (WS / TAS) x sin(delta), where delta is the angle between the desired course and the wind direction. Ground speed follows from the law of cosines or by resolving headwind and crosswind components: GS = sqrt(TAS^2 - XW^2) - HW, where XW is the crosswind component and HW is the headwind component (negative for a tailwind). The E6B flight computer plots this triangle mechanically; this calculator solves it with exact trigonometry.
Headwind and crosswind components
Pilots use the headwind and crosswind components of the wind every time they land. The headwind component (HW) is the portion of the wind that acts directly against the aircraft's motion. A pure headwind reduces ground speed but does not cause drift. A pure tailwind increases ground speed and also does not cause drift but does require a higher ground speed for the same airspeed. The crosswind component (XW) is the portion perpendicular to the course. All the WCA is generated to counteract this component. Every aircraft has a demonstrated crosswind limit published in the Pilot's Operating Handbook; exceed it and directional control on the runway or in the air becomes difficult.
From true heading to magnetic heading
This calculator outputs true heading, which is referenced to geographic north. To set your directional indicator (DI) or HSI in the cockpit you need the magnetic heading, which accounts for local magnetic variation. Magnetic variation is the difference between true north and magnetic north at your location; it changes slowly over time and varies by location. Easterly variation is subtracted from true heading to get magnetic heading; westerly variation is added. For example, if your true heading is 085 degrees and the magnetic variation is 10 degrees west, your magnetic heading is 085 + 10 = 095 degrees. Obtain current magnetic variation from your sectional chart, terminal procedures, or your GPS system.
Crosswind limits by aircraft category
| Aircraft category | Typical max crosswind (kt) | Example type |
|---|---|---|
| Training single (light) | 12-15 | Cessna 172, Piper PA-28 |
| General aviation single | 15-17 | Cirrus SR22, DA40 |
| Twin piston | 17-20 | Piper Seminole, Beechcraft Baron |
| Turboprop commuter | 20-25 | King Air, PC-12 |
| Regional jet | 25-30 | Embraer E175, CRJ-700 |
| Commercial jet (narrow) | 30-38 | Boeing 737, Airbus A320 |
Typical demonstrated crosswind limits. Always check your specific aircraft POH/AFM.
Frequently asked questions
What is the formula for wind correction angle?
The exact formula uses the law of sines on the wind triangle: WCA = arcsin((wind speed / true airspeed) x sin(wind angle)), where wind angle is the angle between your true course and the direction from which the wind blows. For small angles there is a rule-of-thumb approximation: WCA (degrees) is approximately (wind speed / TAS) x sin(wind angle) x 60, but the exact formula is more accurate and is what this calculator uses.
What is the difference between true course and true heading?
True course (TC) is the direction you want to travel over the ground, measured from true north. True heading (TH) is the direction the aircraft nose actually points. When wind is present, these two angles differ by the WCA. You fly the heading, but you track the course. Magnetic course and magnetic heading are the same values with local magnetic variation applied.
How does a crosswind change my ground speed?
A pure crosswind (perpendicular to your course) does not change ground speed directly, but when you correct for it by crabbing, the effective TAS component along your course becomes slightly less than TAS, so ground speed decreases by a small amount: GS = sqrt(TAS^2 - XW^2). A headwind reduces GS directly; a tailwind increases it. In practice all real-world winds have both a headwind/tailwind component and a crosswind component.
What happens if the wind speed is greater than my airspeed?
If the crosswind component of the wind exceeds the aircraft's true airspeed, there is no heading you can fly to track the desired course. The wind literally blows the aircraft sideways faster than it can fly forward along that component. This situation rarely occurs in normal flight (TAS is usually well above wind speed), but it can arise if you try to fly a course nearly perpendicular to a very strong wind. The calculator will return no result in that case.
What is the rule of 60 for mental WCA calculation?
The rule of 60 is a quick cockpit approximation: WCA (degrees) is approximately 60 x (wind speed / TAS) x sin(wind angle). For small angles sin(angle) is roughly angle/60 (in degrees), which simplifies further. For example, a 30-knot crosswind with 120-knot TAS gives WCA = 60 x (30/120) x 1 = 15 degrees. This is accurate enough for in-flight estimation but the exact arcsin formula is always more precise for preflight planning.
Should I use true or magnetic wind direction?
Winds aloft forecasts in the United States (and most countries) are given in true degrees, so this calculator expects true wind direction. Surface winds reported in METAR and ATIS are given in magnetic degrees. If you are calculating WCA for cruise at altitude, use the winds aloft forecast direction. If you are calculating crosswind components for landing from a METAR, use the runway magnetic heading and the magnetic surface wind direction.