Velocity Calculator
This calculator solves the fundamental velocity equation, v = d / t, for any one of the three variables when you know the other two. Velocity is the rate at which an object changes position, and average velocity over a journey is simply the total distance covered divided by the total time taken. You choose which quantity you want to find by selecting the solve-for option, then enter the two known values. If you are solving for velocity, you provide distance in metres and time in seconds, and the calculator returns your speed in metres per second, kilometres per hour, and miles per hour. If you are solving for distance, you provide velocity in m/s and time in seconds, and the calculator gives you the distance in metres. If you are solving for time, you enter velocity in m/s and distance in metres, and the calculator tells you how long the journey takes in seconds. This tool is suited to physics students working through kinematics problems, sports scientists analysing athlete performance, engineers checking vehicle speeds, and anyone who needs a quick unit-aware speed calculation. The formula gives you average velocity and assumes the speed is constant across the entire distance. If the object is accelerating or decelerating, use the SUVAT kinematic equations solver instead for a more accurate result.
How it works
The three forms of the velocity equation are: v = d / t (velocity), d = v × t (distance), and t = d / v (time). Select which variable you want to find, enter the other two, and the calculator rearranges the formula automatically. Velocity in m/s is converted to km/h by multiplying by 3.6, and to mph by multiplying by 2.23694. The calculator assumes constant velocity throughout the journey, giving average speed for any trip where the pace varies.
Worked example
Usain Bolt set the 100 m world record with a time of 9.58 seconds. Velocity = 100 / 9.58 = 10.44 m/s. Multiplied by 3.6 that is 37.58 km/h, and multiplied by 2.23694 that is 23.35 mph. These are the default values pre-filled above so you can verify the outputs straight away.
Related calculators
- Acceleration Calculator: solve a = (v - u) / t when velocity is changing.
- SUVAT Calculator: solve all five kinematic equations for any three known values.
- Projectile Motion Calculator: find range, height, and flight time for objects launched at an angle.
- Percent Error Calculator: compare your measured velocity against a known true value.