Power is the rate of doing work, or of transferring energy. Two people can lift the same box to the same height, doing the same work, but the one who does it faster is more powerful. This calculator uses P = W ÷ t.
Power is measured in watts (W), where 1 W = 1 J/s. The result is also shown in kilowatts and in mechanical horsepower (1 hp = 745.7 W), used for engines and motors.
| Work done or energy (W) | 3,000 J |
| Time taken (t) | 6 s |
| Power (W) | 500 |
| Power (kW) | 0.5 |
| Power (horsepower) | 0.670511 |
A 60 kg person climbing 5 m in 6 s does about 3,000 J of work, a power of 500 W (0.670511 hp).
Try this example →| Work done or energy (W) | 50,000 J |
| Time taken (t) | 20 s |
| Power (W) | 2,500 |
| Power (kW) | 2.5 |
| Power (horsepower) | 3.35256 |
50 kJ in 20 s is 2.5 kW.
Try this example →Power = work done ÷ time (P = W/t). Its unit is the watt.
About 746 W (mechanical horsepower).
Energy is the amount of work that can be done (J). Power is how fast it is done (J/s = W).
No, kWh is a unit of energy: 1 kWh = 3,600,000 J.