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Energy calculator
Calculate kinetic, potential or thermal energy, or convert energy between units.
Energy calculatorEnergy
KE · PE · Thermal · Unit Converter · Full Analysis
KE = ½mv² | m = mass (kg), v = velocity (m/s)
Energy is quoted in whatever unit its field prefers: joules in physics, kilowatt-hours on bills, calories in food, electronvolts in particle physics. This calculator converts between them exactly, so quantities from different worlds can be compared.
How to use this calculator
- Enter the energy amount.
- Select the unit it is in and the unit you want.
- Press calculate to see the converted value.
One quantity, many costumes
The conversions expose how small everyday energies are beside industrial ones, and how large a food calorie really is (a kilocalorie, despite the label). Keeping the joule as the reference unit, as this calculator does, keeps every comparison honest.
Frequently asked questions
How many joules are in a kilowatt-hour?
3,600,000 joules (3.6 megajoules): 1,000 watts × 3,600 seconds.
Is a food Calorie the same as a chemistry calorie?
No. A food Calorie (capital C) is a kilocalorie, 1,000 small calories, about 4,184 joules. Labels use the big one.
Why so many energy units?
Each field adopted a unit sized to its typical quantities. The physics is one; the calculator's job is translation.