Velocity Calculator
Give it a distance and a time and it hands back average speed — in meters per second and kilometers per hour.
Speed
10.4384m/s
Same speed in km/h
37.58km/h
This is average speed — total distance over total time. Direction turns speed into velocity, so if you also know which way you're heading, the number above is the size of that velocity.
How it works
Average speed is just distance divided by time. Cover 100 meters in 10 seconds and you were moving at 10 m/s on average — even if you sped up and slowed down along the way.
Velocity is speed with a direction attached. The number here is the size of that velocity; point it north or east and you've got the full picture. For straight-line motion the two are the same size, which is why people use the words interchangeably.
The km/h figure is the same speed multiplied by 3.6, handy when you want something that matches a speed limit sign rather than a physics textbook.
Frequently asked questions
What's the difference between speed and velocity?
Speed is how fast, velocity is how fast and in which direction. Walk 3 m/s toward the door and your speed is 3 m/s while your velocity is 3 m/s due door. For a straight path they're the same number.
Is this average or instantaneous velocity?
It's the average over the whole trip. Instantaneous velocity is what a speedometer shows at one moment, and you'd need calculus or a very short time interval to pin that down.
What units should I use?
Distance in meters and time in seconds gives you m/s, the standard SI result. If your distance is in kilometers or your time is in hours, convert first or read the km/h figure instead.