Calculate power, force, or velocity from any two values using P = F × v with watts, horsepower, newtons, and speed units like mph and km/h.

For one-dimensional motion: P = Fv. Use signed force and velocity on the same axis; speed is the velocity magnitude.

Power to Speed Formula

The following formula gives the speed when positive mechanical power and force act parallel to the motion. In one-dimensional signed form it gives velocity; in general, power is the vector dot product of force and velocity.

V = P / F
  • Where V is the speed (distance / time)
  • P is the power (work / time)
  • F is the force

To calculate the speed from power, divide the power by the force.

Power to Speed Conversion Table (Assumes constant force F = 500 N)
Power (kW) Velocity (m/s) Velocity (km/h)
0.51.03.6
0.751.55.4
12.07.2
1.53.010.8
24.014.4
2.55.018.0
36.021.6
48.028.8
510.036.0
7.515.054.0
1020.072.0
1224.086.4
1530.0108.0
2040.0144.0
2550.0180.0
3060.0216.0
4080.0288.0
50100.0360.0
75150.0540.0
100200.0720.0
Formula: v = P ÷ F. Here, F = 500 N constant. Units: P in kW (1 kW = 1000 W), v in m/s; km/h = m/s × 3.6.

How can power be converted into speed?

Power is the rate of doing work. For motion and force along the same axis, signed velocity equals power divided by the nonzero force component. Speed is the magnitude of that velocity; power alone does not determine speed.

How to calculate speed from power?

The following example problem outlines the steps required to calculate speed from power.

First, determine the power of the object. In this example, the power is 100 N*m/s.

Next, determine the force acting on the object. In this problem, the force is measured to be 10 N.

Finally, calculate the velocity using the formula above:

V = P / F

V = 100 / 10

V = 10 m/ s