Energy Converter
Convert between energy units — joules, kilojoules, megajoules, calories, kilocalories, watt-hours, kilowatt-hours and BTU.
1 J = 0.001 kJ
1 J = 0.001 kJ
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Frequently asked questions
How many joules are in a calorie?
One calorie equals 4.184 joules, and one food Calorie (kilocalorie) equals 4,184 joules.
How many joules are in a kilowatt-hour?
One kilowatt-hour equals 3.6 million joules.
What is a BTU?
A British Thermal Unit is the energy needed to heat one pound of water by 1°F; it equals about 1,055 joules.