Gypes

Unit converter

Energy converter

Convert mechanical, electrical, food-energy, and heating units through joules.

Energy and the joule

The joule is the SI unit of energy. One watt-hour equals exactly 3,600 joules because a watt is one joule per second. A kilowatt-hour therefore equals 3.6 million joules.

Calories and food labels

This tool uses the thermochemical calorie: one calorie equals exactly 4.184 joules. A food Calorie, written with a capital C in common usage, is a kilocalorie and equals 4,184 joules.

British thermal units

Several BTU definitions exist. This converter uses the International Table value of approximately 1,055.05585262 joules. Check the convention required by a specific heating or engineering document.

Energy and power are different: energy is an amount, while power is the rate of using or transferring energy. Appliance cost also depends on time, efficiency, and the applicable tariff.