What is a kilowatt-hour?

1 kWh is the energy consumed by a 1 kilowatt appliance running for 1 hour. It equals 3.6 million Joules.

What is the difference between calories and joules?

1 calorie (food) = 4.184 J. The "calorie" in food labels is actually kilocalories (kcal).

Battery capacity is measured in watt-hours (Wh). A 50Wh battery can power a 50W device for 1 hour.

Convert between different energy units: Joule, calorie, kWh, BTU, and more.

Convert between various energy units used in physics, engineering, and everyday applications. Energy is the ability to do work.

A typical household uses 10 kWh per day. Convert to Joules:

1 kWh is the energy consumed by a 1 kilowatt appliance running for 1 hour. It equals 3.6 million Joules.
1 calorie (food) = 4.184 J. The "calorie" in food labels is actually kilocalories (kcal).
Battery capacity is measured in watt-hours (Wh). A 50Wh battery can power a 50W device for 1 hour.