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Work and Power Calculator
Find work in joules, power in watts and efficiency from force, distance, mass, time and useful output energy.
Work, power and efficiency
Result: —
Work done: —
Power: —
Efficiency: —
How to use the Work and Power Calculator
- Choose whether to solve for work, power or efficiency.
- Enter the known force, distance, time and output energy values.
- Read the result with the work, power and efficiency lines.
Features
- Work in joules from force and distance
- Power in watts from work and time
- Efficiency as a percentage
- Runs locally, no uploads
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Frequently Asked Questions
Common questions about the free online work and power calculator.
Enter the force in newtons and the distance in metres and the calculator multiplies them to
give work in joules.
Work equals force multiplied by distance, written as W = F x d, when the force acts along the
direction of motion.
Divide the work done by the time taken. For example 500 joules in 25 seconds is 20 watts of
power.
Power equals work divided by time, written as P = W / t, and it is measured in watts, where
one watt is one joule per second.
Divide the useful output energy by the total input energy and multiply by 100 to express the
answer as a percentage.
It means no energy is wasted, which never happens in real machines. Friction, heat and sound
always remove some energy.
Work is the total energy transferred, while power is how quickly that energy is transferred,
so power adds a time element.
One joule is the work done by a force of one newton moving an object one metre in the
direction of the force.
No. Every calculation runs locally in your browser, so the numbers you enter never leave your
own device.
Yes. It is completely free and unlimited, with no account, no sign-up and no limit on the
number of calculations.
Last updated: October 10, 2026