Mechanical Power Calculator
Find average power from the work done and the time it took — plus the equivalent in horsepower.
How it works
P = W ÷ t · 1 hp = 745.7 W
Power is the rate at which work is done or energy is transferred: the same job done in half the time needs twice the power. Because work is measured in joules and time in seconds, power comes out in watts (1 W = 1 J/s). This is average power over the interval — instantaneous power at any moment can be higher or lower.
Worked example
A hoist raises a load doing 6,000 J of work in 12 s. Power = 6,000 ÷ 12 = 500 W, which is 500 ÷ 745.7 ≈ 0.67 hp.
Sources: Power (physics) — Wikipedia
Frequently asked questions
What is the difference between work and power?
Work is the total energy transferred (in joules); power is how fast that transfer happens (joules per second, i.e. watts). Two motors can do the same work, but the more powerful one finishes sooner.
How do I convert watts to horsepower?
Divide watts by 745.7 for mechanical horsepower. So 500 W is about 0.67 hp, and 1,000 W (1 kW) is about 1.34 hp.
Is this average or instantaneous power?
It is average power over the time interval you enter. If the work is done unevenly, the peak instantaneous power will exceed this average.
Related calculators
This calculator is for educational purposes. Double-check important results before acting on them.