Work, Power, Energy Calculator
Calculate
Try an example
Work done
5,000 J
5,000 J · 5 kJ · 0.001389 kWh · 1.195 kcal · 4.739 BTU · 3,688 ft·lbf
W = F × d × cos θ = 500 N × 10 m × cos 0° = 5,000 J
Calculate work done by a force, kinetic energy, gravitational potential energy and average power in the units you use, with every answer converted to joules, kilowatt-hours, kilocalories, BTU and foot-pounds.
Formula
Worked Example
100 km/h is 27.78 m/s, so KE = 0.5 × 1,500 × 27.78² = 578,700 J. Falling 39.3 m builds up the same speed. At 50 km/h the energy is a quarter as much, equal to a 9.8 m fall.
Frequently Asked Questions
What is the difference between work, energy and power?
Work is energy transferred when a force moves something, and energy is the capacity to do work; both are measured in joules. Power is how fast the work is done, in watts, or joules per second.
How do joules convert to other energy units?
1 kWh is 3.6 million joules, 1 kilocalorie (a food Calorie) is 4,184 J, 1 BTU is 1,055 J and 1 foot-pound is 1.356 J. For power, 1 horsepower is 745.7 W.
Why does speed matter so much in a crash?
Kinetic energy grows with the square of speed, so doubling speed quadruples the energy that brakes, crumple zones and bodies must absorb, and roughly quadruples the braking distance.