How do you calculate the wind correction angle?

Wind correction angle = arcsin(wind speed × sin(wind angle) ÷ true airspeed), where the wind angle is the difference between the wind direction and your course. Flying a 288° course at 110 knots TAS with wind from 350° at 3 knots gives a WCA of about +1°, a true heading of 289°, and a groundspeed of 109 knots.

What is the difference between course and heading?

Course is the path over the ground you want to fly, measured on the chart. Heading is where you point the nose to stay on that path despite the wind. Heading = course + wind correction angle. Apply magnetic variation to true heading to get magnetic heading, and compass deviation to get the compass heading you actually fly.

Are winds aloft given in true or magnetic direction?

Winds aloft forecasts are in degrees true, which matches the true course you measure on a chart, so use them together directly. Only surface winds spoken over the radio (ATIS, AWOS, tower) are magnetic. The memory aid is: written true, spoken magnetic.

Wind Correction Angle Calculator: Heading & Groundspeed

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Wind correction angle = arcsin(wind speed × sin(wind angle) ÷ TAS); groundspeed = TAS × cos(WCA) − wind speed × cos(wind angle). This is the wind triangle, the calculation at the heart of every E6-B and every nav log line: point the nose into the wind just enough that your track stays on course, then accept whatever groundspeed is left.

True course (°)

Measured on the chart, in degrees true

True airspeed (kt)

From the true airspeed calculator or your POH

Wind direction (° true)

Direction the wind is from, per the winds aloft forecast (already true)

Wind speed (kt)

Magnetic variation (°, optional)

West positive, east negative ("east is least"). From the isogonic line on your chart

▬ course ▬ heading ▬ wind

Enter the wind to solve the triangle.

Wind correction – crab angle

True heading – course + WCA

Magnetic heading – what you fly on the DG

Groundspeed – use for leg times

How the wind triangle works

Three vectors close a triangle: your airspeed vector (where the nose points, at TAS), the wind vector, and the resulting track over the ground. Planning solves it backwards: you know the track you want (the course), the TAS you will fly, and the forecast wind; you need the heading and the groundspeed that fall out.

Wind angle = wind direction − course (how far off the nose the wind is from).
WCA = arcsin(wind speed × sin(wind angle) ÷ TAS). Positive means crab right, negative crab left.
True heading = course + WCA.
Groundspeed = TAS × cos(WCA) − wind speed × cos(wind angle). A quartering headwind steals speed twice: once as headwind, once because your crab points some of your TAS sideways.

Then convert to what the panel shows: magnetic heading = true heading + westerly variation (subtract easterly: "east is least, west is best"), and compass heading adds the deviation card correction.

How pilots use it

Filling the nav log: one triangle per leg turns chart courses and forecast winds into the heading column and the groundspeed column; groundspeed then drives ETE and fuel. This is exactly what a CX-3's trip planner or an EFB does per leg.
Sanity-checking the magic: when the EFB says "fly 289°," a pilot who can see that a light quartering tailwind means a small left-or-right crab and a couple of knots gained will catch a fat-fingered wind entry instantly.
In flight, in reverse: if you know your heading, TAS, track, and groundspeed (GPS gives you the last two), the same triangle run backwards reveals the actual wind at altitude, which is worth knowing before descending toward a gusty runway.
The quick mental version: maximum drift (wind speed ÷ TAS in NM per minute × 60) scaled by the clock rule. At 120 knots TAS, a 20-knot direct crosswind needs about 10° of crab; half the angle off the nose, half the crab.

Worked example, from an actual nav log

Course 288° true, TAS 110 knots, winds aloft 350° at 3 knots (a calm Pacific Northwest morning):

Wind angle = 350 − 288 = 62° off the right nose
WCA = arcsin(3 × sin 62° ÷ 110) ≈ +1° (crab right)
True heading = 289°; with 17° east variation, magnetic heading = 272°
Groundspeed = 110 × cos 1° − 3 × cos 62° ≈ 109 knots

Now stiffen the wind to 350° at 25 knots: the crab grows to 12° and groundspeed drops to 96 knots, a 12% longer leg with the same fuel flow. That is why the triangle gets re-run whenever the forecast changes.

Bonus: find the actual winds aloft in flight

The same triangle runs backwards. In cruise you know four things: the heading you're holding, your TAS, and (from GPS) your actual track and groundspeed. Enter them and out comes the wind that must be causing the difference: the flight-computer "wind correction" function, and a better wind report than any forecast.

True heading flown (°)

True airspeed (kt)

Actual track (°)

"TRK" on your GPS

Groundspeed (kt)

Wind from – degrees true

Wind speed – kt

Your crab – heading minus track

Common Questions

Why does a direct crosswind still slow me down?

Because you have to crab into it. The component of your TAS that points into the wind is spent holding the track, not moving you along it, so groundspeed is TAS × cos(WCA) even with zero headwind component. A 90°, 30-knot wind on a 100-knot airplane costs about 5 knots of groundspeed purely from the 17° crab.

When is there no solution to the wind triangle?

When the crosswind component of the wind exceeds your TAS, no heading can hold the course; the calculator will tell you. Short of that, a strong tailwind-quartering wind can also produce a groundspeed near zero into a strong headwind. If your trainer flies 90 knots and the winds aloft say 60, the triangle still solves, but the fuel math may not.

Do I apply variation before or after the wind correction?

After. Work the whole triangle in true (chart course and winds aloft are both true), then convert: true course → apply WCA → true heading → apply variation → magnetic heading → apply deviation → compass heading. The classic memory aid is "True Virgins Make Dull Company" (True, Variation, Magnetic, Deviation, Compass).

Related tools and guides

True Airspeed Calculator

The TAS input for this triangle, from CAS, altitude, and temperature.

Time-Speed-Distance Calculator

Turn the groundspeed into leg times and an ETA.

Crosswind Calculator

The same wind, resolved against a runway instead of a course.

Winds aloft, checked automatically

FlightDecide pulls the forecast winds for your route and window and scores them with ceilings, visibility, NOTAMs, fuel, performance, and W&B, with the raw data one tap away.

Get FlightDecide on the App Store

Educational tool for flight-planning practice. It is advisory only and not a substitute for your POH, an official weather briefing, or your own judgment as pilot in command (14 CFR 91.3). Sources: FAA Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25C), Ch. 16. Last reviewed: July 17, 2026.