Calculate aircraft ground speed from true airspeed, wind speed, and wind direction. Includes headwind/crosswind components and wind correction angle.
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 a student pilot preparing cross-country flights, an instrument pilot filing IFR flight plans, or an aviation enthusiast exploring wind effects, this tool provides instant, accurate wind triangle solutions without the need for an E6B flight computer. Check the example with realistic values before reporting.
Solving the wind triangle by hand with an E6B or manual vector diagram is time-consuming and error-prone. This calculator instantly computes all wind components — ground speed, headwind, crosswind, crab angle, and track — from four simple inputs. It is perfect for quick cross-checks during flight planning. Keep these notes focused on your operational context.
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
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.
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.
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.
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.
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.
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.
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.
Yes, with a tailwind. If TAS is 250 kt and the tailwind is 30 kt, the ground speed is approximately 280 kt.
TAS depends on indicated airspeed, altitude (pressure), and temperature. This calculator assumes you already know TAS. Use a TAS calculator separately if needed.
It performs the same wind-triangle calculation as the wind side of an E6B, but with digital precision and without the need for physical manipulation. Use this as a practical reminder before finalizing the result.