Free wind correction angle calculator
Enter your true airspeed, the wind, and your desired course to get the wind correction (crab) angle, the heading to fly, the crosswind and headwind components, and your ground speed — solved from the E6B wind triangle, updated live, as you type.
On this page12 sections
For flight planning awareness, not a substitute for an official briefing or your E6B. How accurate is this?
Results are estimates. Consult a professional.
What the wind correction angle (crab angle) is
The wind correction angle (WCA), also called the crab angle, is the small angle you point the nose of an aircraft away from your desired course to cancel out a crosswind. Because wind pushes the aircraft sideways through the air mass it flies in, the path you actually trace over the ground (your course) is not the direction the nose points (your heading). To track the course you want, you head a few degrees into the wind — you "crab."
This calculator solves the classic E6B wind triangle. Give it your true airspeed, the wind speed and direction, and the course you want to fly, and it returns the wind correction angle (with the direction to crab), the heading to fly, the crosswind and head- or tailwind components, and your resulting ground speed.
The rule is simple: crab into the wind. If the wind comes from your right, you turn the nose right of course; if it comes from your left, you turn left. The stronger the crosswind relative to your airspeed, the larger the angle you need.
How the wind correction angle is calculated
The wind triangle relates three vectors: where the aircraft moves through the air (true airspeed along the heading), how the air itself moves (the wind), and the result over the ground (ground speed along the course). The calculator first measures the wind relative to your course, then splits it into the part that pushes you sideways (the crosswind) and the part that pushes you forward or back (the head- or tailwind).
What you need to enter
Four numbers solve the triangle. Three come straight from your flight plan and weather briefing; the fourth is the leg you want to fly.
True airspeed (TAS)
Your speed through the air in knots — indicated airspeed corrected for altitude and temperature, not the raw number on the airspeed indicator. TAS is the speed the wind triangle is built on, because the wind acts on the air mass you fly through. The same thin, warm air that raises true airspeed also raises your density altitude, so the two often climb together.
Wind speed and direction
The wind at your altitude, from a winds-aloft forecast or ATIS. Direction is the bearing the wind blows from, in degrees. Note that winds-aloft forecasts are given in degrees true, while ATIS and the tower report magnetic — convert to a common reference before you compare a heading to a course.
Desired course
The direction of your leg over the ground, in degrees — the line you drew on the chart. The calculator finds the heading that, once the wind has had its way, leaves you tracking exactly this course.
A worked example using the wind correction angle calculator
You are flying a course of 360° (due north) at a true airspeed of 120 kt. The winds-aloft forecast gives the wind from 040° at 30 kt — a wind coming over your right shoulder. Which way, and how far, do you crab, and how fast will you actually be going over the ground?
Step 1 — Find the wind angle relative to course
The wind is from 040° and the course is 360°, so the wind angle is 040 − 360 = 40° off the nose, from the right.
Step 2 — Split the wind into crosswind and headwind
Crosswind = 30 × sin(40°) = 19.3 kt from the right. Head/tailwind = 30 × cos(40°) = 23.0 kt of headwind.
Step 3 — Solve for the correction angle and heading
WCA = arcsin(19.3 ÷ 120) = 9.2° to the right. So you fly a heading of 360 + 9.2 ≈ 009° to track a 360° course.
Step 4 — Read the ground speed
Ground speed = 120 × cos(9.2°) − 23.0 ≈ 95 kt. The headwind has cost you about 25 kt over the ground even though you crabbed only 9°.
Wind correction angle chart by crosswind and airspeed
The wind correction angle depends only on the crosswind component as a fraction of true airspeed — not on the wind's total strength. This chart gives the WCA in degrees for a range of crosswind components and airspeeds. Read down to your crosswind component (wind speed × sin of the wind angle), across to your true airspeed.
| Crosswind | 90 kt TAS | 120 kt TAS | 150 kt TAS |
|---|---|---|---|
| 10 kt | 6.4° | 4.8° | 3.8° |
| 20 kt | 12.8° | 9.6° | 7.7° |
| 30 kt | 19.5° | 14.5° | 11.5° |
| 40 kt | 26.4° | 19.5° | 15.5° |
Wind correction angle = arcsin(crosswind ÷ TAS). The angle grows quickly once the crosswind passes a third of your airspeed; if the crosswind ever equals your true airspeed, the course cannot be held at all.
The crab angle and crosswind landings
The same crab angle shows up on every crosswind approach. As you fly the final approach course, a crosswind drifts you toward the downwind side, so you point the nose into the wind to track the runway centerline — exactly the WCA this calculator finds, with the approach course as your "course" and the surface wind as the wind.
The difference is what happens at touchdown. You cannot land crabbed — the wheels must roll straight down the runway. In the common crab-to-kick-out technique, you hold the crab down final, then just before the wheels touch you use rudder to align the nose with the centerline (the "kick"), adding aileron into the wind to stop the drift. Knowing the crab angle in advance tells you how strong the crosswind is and how much you will have to take out in the flare.
How accurate is this wind correction angle calculator?
The wind triangle is exact geometry, not an approximation: given the true airspeed, the wind, and the course, the wind correction angle, heading, and ground speed are computed exactly. The accuracy of the answer is therefore the accuracy of your inputs — chiefly the forecast wind, which is the least certain number in any flight plan.
Two limits are worth knowing. First, the tool works entirely in true directions and true airspeed; for an actual compass heading you must apply magnetic variation and compass deviation, and you must convert indicated airspeed to true. Second, if the crosswind component ever equals or exceeds your true airspeed, no heading can hold the course — the calculator flags this rather than returning a meaningless angle.
Wind correction angle definitions
Frequently asked questions about the free wind correction angle calculator
About this Wind correction angle calculator
This wind correction angle calculator runs entirely in your browser. Nothing you enter is sent anywhere — your airspeed, wind, and course stay on your device, and the wind-triangle solution updates instantly as you adjust them.
It uses the standard E6B wind-triangle method from the FAA Pilot's Handbook. For more flight-planning tools, see our other weather calculators, or browse the full library of free calculators.