Ground Speed Calculator
Use our ground speed calculator to calculate ground speed from distance and time. Includes the ground speed formula, how to calculate ground speed in flight (airspeed ± wind), and answers like is ground speed faster than airspeed.
What Is Ground Speed?
Ground speed is how fast an object moves relative to the ground. In aviation, it’s the actual speed over the Earth’s surface, which can differ from airspeed because of wind.
If you measure a trip’s distance and the time it took, you can calculate ground speed directly. In flight, you can also estimate ground speed from airspeed and wind: a tailwind increases ground speed, and a headwind reduces it.
Ground speed is a magnitude (a speed). When you add direction (like northbound at 120 knots), you’re talking about velocity—speed in a particular direction.
Ground Speed Formula
The simplest way to compute ground speed is distance divided by time. In aviation, ground speed is related to airspeed and wind along the flight path.
Make sure distance and time units match (e.g., miles per hour, km/h, knots).
Add for tailwind, subtract for headwind (using the wind component in the direction of travel).
This is the standard “calculate ground speed” method.
A headwind of 15 kt would give ≈ 105 kt instead.
How to Calculate Ground Speed
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Enter the distance traveled.
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Enter the total travel time.
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The calculator computes ground speed = distance ÷ time.
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If you’re calculating ground speed in flight, use airspeed and the wind component along your track: ground speed ≈ airspeed + tailwind component (or − headwind component).
Frequently Asked Questions
Ground speed is the speed of an object relative to the ground (its rate of travel over the Earth’s surface).
Use ground speed = distance ÷ time. For example, 120 km in 2 hours is 60 km/h.
A simple estimate is ground speed ≈ airspeed ± wind component along the flight path. Tailwind increases ground speed; headwind decreases it.
Sometimes. With a tailwind, ground speed can be greater than airspeed. With a headwind, ground speed is less than airspeed. With no wind, they’re approximately the same.
That’s velocity. Speed is how fast you’re moving; velocity includes both speed and direction.
Any speed unit works as long as your distance and time units match (mph, km/h, m/s, knots, etc.). In aviation, knots are common.