Enter your aircraft's True Airspeed (TAS), heading, wind speed, and wind direction to calculate your ground speed and wind correction angle. The calculator uses vector math to find how fast your aircraft is actually moving relative to the Earth's surface, accounting for wind drift.
Ground Speed
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Track Angle
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Wind Correction Angle (WCA)
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Drift Angle
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Ground speed is the horizontal velocity of an aircraft relative to the Earth's surface. Unlike airspeed, which measures speed through the surrounding air mass, ground speed accounts for wind effects and directly determines how quickly a plane covers distance over the ground — making it essential for calculating flight times and fuel requirements.
True airspeed (TAS) is the speed of the aircraft relative to the air around it. Ground speed is the aircraft's speed relative to the ground below. A headwind reduces ground speed below TAS, while a tailwind increases it above TAS. In still air, the two values are equal.
Ground speed is calculated using the vector relationship between TAS and wind velocity: GS = √(TAS² + V_wind² − 2·TAS·V_wind·cos(heading − wind_direction)). You need to account for both the magnitude and direction of the wind relative to the aircraft's heading.
The wind correction angle is the angular difference between an aircraft's heading (where the nose points) and its track (the actual path over the ground). Pilots apply WCA to compensate for crosswind drift and keep the aircraft on its intended course.
The course (or track) is the actual path the aircraft follows over the ground, while the heading is the direction the aircraft's nose is pointing. In the presence of wind, these two angles differ by the wind correction angle. Pilots point the nose slightly into the wind to maintain the desired course.
It depends on the wind. With a tailwind, ground speed is greater than true airspeed. With a headwind, ground speed is less than true airspeed. A direct crosswind reduces ground speed slightly compared to TAS. In still air, ground speed and true airspeed are equal.
With a direct 20-knot headwind (wind blowing straight at the aircraft), the ground speed would be approximately 60 knots (80 − 20). For crosswinds or tailwinds, the relationship is more complex and requires the full vector formula used by this calculator.
Ground speed directly determines your time en route and fuel consumption over any given distance. Flight dispatchers and pilots use it to calculate estimated arrival times, required fuel loads, and to optimize routing. A higher ground speed (e.g., via a tailwind) saves fuel and time, while a headwind increases both.