UnitsUp to date · Jan 15, 2026
Joule (J)
The SI unit of energy. One watt-second equals one joule. One kWh equals 3.6 million joules. Rarely used in consumer energy contexts but common in physics and engineering.
Why It Matters
Scientific literature and some international product ratings use joules. Knowing the conversion (1 kWh = 3.6 MJ) bridges the gap between technical papers and practical energy decisions.
Related Tools
Related Terms
kWh (Kilowatt-hour)
A unit of energy equal to 1,000 watts used for one hour. This is how utilities measure your electricity usage.
BTU (British Thermal Unit)
A traditional unit of heat energy, approximately the energy needed to heat one pound of water by one degree Fahrenheit. One kWh equals about 3,412 BTU. Used to rate furnaces, water heaters, and heating/cooling systems.