Megawatt-hours to Kilojoules (MWh to kJ)

1 megawatt-hour equals 3,600,000 kilojoules exactly.

1 megawatt-hour = 3,600,000 kilojoules

How to convert megawatt-hours to kilojoules

To convert megawatt-hours to kilojoules, multiply the number of megawatt-hours by 3,600,000. This factor is exact. To go the other way, multiply kilojoules by 2.777777778×10⁻⁷ (rounded).

kilojoules = megawatt-hours × 3,600,000

Example: 10 megawatt-hours = 36,000,000 kilojoules.

The 'calorie' on food labels is really a kilocalorie. The thermochemical calorie (4.184 J) is used here unless marked IT.

About these units

Megawatt-hour (MWh)

Metric (SI)Current unit

1,000 kilowatt-hours. Used for power-plant output and wholesale electricity trading.

A megawatt-hour is a thousand kilowatt-hours, and it is where electricity stops being a household quantity and becomes an industrial one. It is the energy of a 1 MW load running for an hour, equal to 3.6 GJ, and it is used for metering large industrial customers and for the output of power plants.

The average US household used 893 kWh a month in 2020, so one megawatt-hour is a little more than a month of an ordinary home's electricity. Scaled up further, sustaining about 114 MW for a full year amounts to one terawatt-hour, the unit used for national generation figures.

Indian usage gives a neat link: a million of what Indians call units, meaning kilowatt-hours, is a gigawatt-hour, which is 1,000 MWh. Wholesale deals, plant ratings and grid statistics are typically quoted at this scale because the numbers stay readable.

1 megawatt-hour = 3,600,000,000 joules (exactly).

Sources: Wikipedia: Kilowatt-hour; Wikipedia: Watt-hour; Wikipedia: Orders of magnitude (energy)

Kilojoule (kJ)

Metric (SI)Current unit

1,000 joules. Food labels in many countries give energy in kilojoules.

Most food labels around the world express energy in kilojoules, which is the calorie's long retirement in action. The calorie came out of heat measurement, and the 1948 CGPM resolution stated that the joule should be preferred as the unit of heat. Labels that still show kilocalories alongside kilojoules rely on the thermochemical calorie of exactly 4.184 joules, so one kilocalorie is about 4.184 kJ.

The kilojoule is a convenient size for a body's daily bookkeeping. A person at rest uses about 5,000 kJ, or roughly 1,200 kcal, per day, and the recommended intake for a moderately active woman is given as 2,000 food calories, which is about 8,400 kJ.

Smaller physical comparisons land in the same range. One watt-hour is 3.6 kJ, a British thermal unit is about 1.1 kJ, exploding a gram of TNT releases about 4.2 kJ, and an alkaline AA battery holds about 9 kJ.

1 kilojoule = 1,000 joules (exactly).

Sources: Wikipedia: Kilojoule; Wikipedia: Joule; Wikipedia: Orders of magnitude (energy)

Related conversions

See all energy units.