Acceleration calculator
Enter the two speeds and the time between them to get the average acceleration. A negative value means slowing down.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter speed unit, initial speed, final speed and time.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
a = (v − u) ÷ t, where u is the initial speed, v the final speed and t the time. In g units: a ÷ 9.80665.
Example
Inputs: Speed unit = Kilometers per hour (km/h), Initial speed = 0, Final speed = 100, Time = 10 s. Result: Acceleration: 2.7778 m/s²; In g: 0.2833 g; Change in speed: 27.7778 m/s.
Limits and caveats
- Gives the average acceleration over the interval; the real value may vary moment to moment.
- Assumes motion along a straight line.
Questions about this tool
What does negative acceleration mean?
The speed is dropping over time, so the object is slowing down in its direction of travel, as when braking.
What is the acceleration of a car doing 0 to 100 km/h in 10 seconds?
100 km/h is about 27.78 m/s, so the average acceleration is about 2.78 m/s², roughly 0.28 g.
Which g value is used?
Standard gravity, 9.80665 m/s², an exactly defined value used to compare with free fall on Earth.