Example data
Use these sample cases to verify behavior. Values are rounded to one decimal for display.
| Course (°) | TAS (kt) | Wind (from °/kt) | Crosswind (kt) | Headwind (kt) | WCA (°) | True heading (°) | Ground speed (kt) |
|---|---|---|---|---|---|---|---|
| 090 | 120 | 150 / 25 | 21.7 | 12.5 | 10.4 | 100.4 | 130.5 |
| 270 | 110 | 320 / 18 | 13.8 | 11.6 | 7.2 | 277.2 | 120.7 |
| 360 | 95 | 080 / 30 | 29.5 | 5.2 | 18.1 | 18.1 | 95.5 |
| 045 | 140 | 010 / 15 | -8.6 | 12.3 | -3.5 | 41.5 | 152.0 |
| 180 | 105 | 210 / 22 | 11.0 | 19.1 | 6.0 | 186.0 | 123.5 |
Negative crosswind means the wind pushes you right, so you steer left (negative WCA).
Formula used
Let TC be the desired true course, TAS true airspeed, and WD wind direction (from).
Define the relative wind angle:
θ = WD − TC (wrapped to −180°…+180°)
- Crosswind:
XW = W × sin(θ) - Headwind:
HW = W × cos(θ) - Wind correction angle:
WCA = asin(XW / TAS) - Ground speed:
GS = TAS × cos(WCA) + HW - True heading:
TH = TC + WCA
Magnetic and compass headings are derived using variation and deviation with “East is least, West is best”.
How to use this calculator
- Enter your desired track/course in degrees.
- Enter true airspeed and choose its unit.
- Enter wind direction and wind speed (from direction is standard).
- Click Calculate to get WCA, headings, and ground speed.
- Optional: open advanced options to add variation and deviation.
- Use Download CSV or Download PDF to save results.
Wind correction angle insights
Use it for enroute planning, training checks, and quick dispatch calculations before takeoff.
1) Why WCA matters
Wind correction angle keeps your ground track on the planned course. Drift grows quickly: 5° held for 30 minutes at 120 kt creates about 5.2 NM of sideways error. WCA adds an offset so motion through air cancels wind drift.
2) Crosswind and headwind components
The calculator splits wind into crosswind and headwind using trigonometry. With wind speed W and relative angle θ (wind from minus course), crosswind is W·sin(θ) and headwind is W·cos(θ). A 25 kt wind at 60° off course gives about 21.7 kt crosswind and 12.5 kt headwind.
3) How ground speed is formed
Ground speed is not simply TAS plus or minus wind. Turning into the wind reduces forward airspeed to TAS·cos(WCA). With TAS 120 kt and WCA 10°, forward airspeed is about 118.2 kt. Add headwind or tailwind components for timing and fuel planning.
4) When conditions exceed limits
When crosswind approaches TAS, required WCA becomes large and holding the planned track may be impossible. If crosswind equals TAS, theoretical WCA is 90°. The tool clamps the asin() ratio to avoid math errors, but very large WCA should be treated as a feasibility warning.
5) True, magnetic, and compass heading
The wind triangle uses true course and true heading. To fly magnetic, apply variation: Magnetic = True − EastVar or + WestVar. Then apply deviation to get compass heading. These corrections change display headings, not WCA or ground speed.
6) Getting inputs right
Enter directions in degrees 0–360 and keep speed units consistent. Aviation winds are usually reported as “from” a direction, meaning air comes from that bearing. If your source gives a “to” direction, switch the selector so the calculator flips it by 180° internally.
7) Using examples to verify signs
Use the example table as a sanity check. Wind from the right should produce positive crosswind and positive WCA, meaning steer right of course. Wind from the left produces negative values. If signs look reversed, recheck course entry and the wind “from/to” setting.
FAQs
1) What is wind correction angle?
Wind correction angle is the steering offset into the wind that keeps your ground track aligned with your planned course. Positive WCA means steer right; negative WCA means steer left.
2) Why can ground speed be higher than airspeed?
A tailwind component adds to your forward motion over the ground. If that tailwind is larger than the small forward‑speed loss caused by the heading change, ground speed can exceed airspeed.
3) Should I enter wind direction “from” or “to”?
Most aviation reports give wind direction as “from.” If your source provides the direction the wind blows “to,” choose the “Wind TO” option so the calculator converts it correctly.
4) What if crosswind is greater than airspeed?
If crosswind is near or above your airspeed, the required correction can become extreme and holding the planned track may be impossible. Treat very large WCA values as a warning to recheck feasibility and safety.
5) Do variation and deviation change WCA or ground speed?
No. WCA and ground speed come from the wind triangle using true course and true heading. Variation and deviation only translate the resulting true heading into magnetic and compass headings.
6) Which speed unit should I use?
Use any unit you prefer. The calculator converts internally and returns ground speed, headwind, and crosswind in the same unit you selected for airspeed, which keeps planning consistent.