Physics
Instant, private, and free
Ground Speed Calculator.
Add explicitly entered east/north airspeed and wind vectors to calculate ground speed and track bearing.
Set your values
Results update as you type.
Results update automatically as you type.
Components are signed vectors: east and north are positive, and wind is entered as a vector toward its travel direction. No navigation or weather data is inferred.
Use Cases
Flight Planning for Pilots
Pilots can use this calculator to determine their actual ground speed and track when they know their airspeed components and the wind components at their altitude.
Example: If airspeed is 100 m/s east and 0 m/s north, with wind 10 m/s east and 5 m/s north, ground speed is about 110.4 m/s at a track of 2.6°.
Sailing and Marine Navigation
Sailors can estimate their speed over ground and course made good by inputting the boat's speed through water and the current components.
Example: Boat speed 5 m/s north, current 1 m/s east gives ground speed 5.1 m/s and track 11.3° east of north.
Frequently Asked Questions
- How is ground speed calculated from the input vectors?
- The calculator adds the east and north components of airspeed and wind separately to get the ground velocity components. Then it computes the magnitude as the square root of the sum of squares of these components, and the track as the angle relative to north using the atan2 function.
- What units are used for the inputs and outputs?
- All input fields (airspeed east, airspeed north, wind east, wind north) are in meters per second (m/s). The ground speed output is also in m/s, and the track is given in degrees, typically measured clockwise from true north.
- Can I use this calculator for any type of aircraft or just small planes?
- This calculator is a general physics tool that works for any object moving through a fluid, including aircraft, boats, or even birds. It assumes a constant wind vector and does not account for factors like air density or altitude, so it's best for basic navigation estimates.
Tips & Common Mistakes
Tips
- Ensure you use consistent signs: east and north are positive, west and south are negative.
- Double-check your wind components: they should be the direction the wind is blowing toward, not from.
- For accurate results, use the same units (m/s) for all inputs; convert if necessary.
- Remember that track is measured clockwise from north, so 90° means east, 180° south, etc.
Common Mistakes to Avoid
- Entering wind direction as 'from' instead of 'toward' – this flips the wind vector and gives incorrect ground speed.
- Forgetting to include the sign for west or south components, leading to wrong vector addition.
- Mixing units, such as using knots for airspeed and m/s for wind, which invalidates the calculation.
Last updated: August 13, 2026