What is the difference between airspeed and ground speed?

Airspeed is the speed of the aircraft relative to the surrounding air mass. Ground speed is the speed relative to the earth's surface. They differ by the wind vector.

What is wind correction angle?

The wind correction angle (WCA), also called the crab angle, is the angle the pilot must point the nose into the wind to maintain the desired ground track. It compensates for crosswind drift.

Why does wind direction say "FROM"?

Aviation convention reports wind as the direction it blows FROM. A wind from 270° means the wind is coming from the west. This matches METAR and ATIS reports.

Can ground speed be higher than airspeed?

Yes, with a tailwind. If TAS is 250 kt and the tailwind is 30 kt, the ground speed is approximately 280 kt.

What about altitude and temperature effects on TAS?

TAS depends on indicated airspeed, altitude (pressure), and temperature. This calculator assumes you already know TAS, so it can focus on the wind triangle itself.

Is this the same as an E6B flight computer?

Yes. It performs the same wind-triangle calculation as the wind side of an E6B, but with a direct digital result.

Ground Speed Calculator

Calculate aircraft ground speed from true airspeed, wind speed, and wind direction. Includes headwind/crosswind components and wind correction angle.

Speed Unit

True Airspeed (TAS)

Wind Speed

Wind Direction (FROM)

Aircraft Heading

Ground Speed

230.0 kt

TAS: 250.0 kt

Headwind Component

20.0 kt

Headwind

Crosswind Component

0.0 kt

Magnitude of crosswind

Wind Correction Angle

0.0°

Crab angle to maintain course

Track (Course)

0°

Actual path over ground

Time for 100 NM

26.1 min

At current ground speed

Speed Comparison

Airspeed

250 kt

Ground Spd

230 kt

Beaufort Wind Scale Reference

Scale	Description	Wind (kt)
0	Calm	< 1
1	Light air	1–3
2	Light breeze	4–6
3	Gentle breeze	7–10
4	Moderate breeze	11–16
5	Fresh breeze	17–21
6	Strong breeze	22–27
7	Near gale	28–33
8	Gale	34–40

Planning notes, formulas, and examples

About the Ground Speed Calculator

Ground speed is the actual speed at which an aircraft moves over the earth's surface. It differs from true airspeed (TAS) because of wind — a headwind reduces ground speed, a tailwind increases it, and a crosswind requires a crab angle to stay on course. Knowing the ground speed is essential for flight planning, fuel calculations, and ETA estimation.

This Ground Speed Calculator takes your true airspeed, wind speed, and both directions (wind and heading) to compute the ground speed, headwind and crosswind components, and the wind correction angle (crab angle) needed to maintain your desired track. It supports knots, mph, and km/h.

Whether you are planning a cross-country flight, checking an IFR leg, or comparing wind effects in training, This calculator gives the full wind-triangle result in one place without manual vector math or an E6B flight computer.

When This Page Helps

Solving the wind triangle by hand with an E6B or manual vector diagram is time-consuming and error-prone. This calculator turns TAS, wind speed, wind direction, and heading into ground speed plus headwind and crosswind components immediately.

How to Use the Inputs

Select your preferred speed unit (knots, mph, or km/h).
Enter your True Airspeed (TAS) — the speed your aircraft moves through the air.
Enter the wind speed as reported (in knots by default).
Enter the wind direction (the direction the wind is blowing FROM, in degrees).
Enter your aircraft heading in degrees.
Read the ground speed, headwind/crosswind components, crab angle, and track.
Use the speed comparison bars to visualize the headwind or tailwind effect.

Formula used

Ground Speed (vector addition):
  GS_x = TAS − W_s × cos(W_d − HDG)
  GS_y = −W_s × sin(W_d − HDG)
  GS = √(GS_x² + GS_y²)

Wind Correction Angle:
  WCA = arcsin(W_crosswind / TAS)

Where:
  TAS = true airspeed
  W_s = wind speed
  W_d = wind direction (FROM)
  HDG = aircraft heading

Example Calculation

Result: 230 kt ground speed

With a TAS of 250 knots and a direct headwind of 20 knots, the ground speed is 250 − 20 = 230 knots. No crab angle is needed because the wind is directly on the nose.

Tips & Best Practices

Wind reports in METARs are already in the FROM direction — enter them directly.
For crosswind-only scenarios, set the wind direction 90° off your heading.
Ground speed is what determines your actual ETA and fuel burn over a route.
At higher altitudes, upper-level winds are often much stronger than surface winds.
Always verify ground speed in flight using GPS as a cross-check against planning estimates.

The Aviation Wind Triangle

Every cross-country flight involves solving the "wind triangle" — the vector relationship between the aircraft's heading and TAS, the wind direction and speed, and the resulting track and ground speed. Before GPS, pilots relied on the E6B flight computer or manual vector diagrams on charts. Today the calculation is done digitally, but understanding the underlying vector math remains essential for any pilot.

Headwind and Crosswind Components

The headwind component is the portion of the wind speed that directly opposes (or aids) your direction of travel. The crosswind component is the perpendicular portion that causes drift. Runway crosswind limits for an aircraft are typically specified in knots. Knowing how to decompose the wind into these components is critical for takeoff and landing decisions.

Practical Flight Planning

When filing a flight plan, ground speed determines leg times and therefore fuel requirements. An unexpected headwind increase can turn a comfortable fuel reserve into a diversion scenario. Conversely, a stronger-than-forecast tailwind can shorten the flight. Monitoring ground speed in flight — comparing GPS ground speed to planned ground speed — is one of the simplest and most important checks a pilot can make.

Sources & Methodology

Last updated: March 7, 2026

Frequently Asked Questions

Airspeed is the speed of the aircraft relative to the surrounding air mass. Ground speed is the speed relative to the earth's surface. They differ by the wind vector.