Megawatt-hours to British Thermal Units (MWh to BTU)

1 megawatt-hour equals 3,412,141.633 British thermal units (rounded).

1 megawatt-hour = 3,412,141.633 British thermal units

How to convert megawatt-hours to British thermal units

To convert megawatt-hours to British thermal units, multiply the number of megawatt-hours by 3,412,141.633. The factor is rounded to 10 significant digits. To go the other way, multiply British thermal units by 2.930710702×10⁻⁷ (rounded).

British thermal units = megawatt-hours × 3,412,141.633

Example: 10 megawatt-hours = 34,121,416.33 British thermal units.

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)

British Thermal Unit (BTU)

US & ImperialCurrent unit

The International Table BTU, exactly 1,055.05585262 joules. The energy to heat one pound of water by one degree Fahrenheit; used for heating, cooling and gas appliances in the US.

Few energy units come in as many versions as the British thermal unit. It was defined as the heat needed to raise one pound of liquid water by one degree Fahrenheit, but because water's heat capacity shifts slightly with temperature, definitions differ by up to 0.5 percent: about 1,054.35 J for the thermochemical Btu, 1,054.80 J at 59 degrees Fahrenheit (used for American natural gas pricing), 1,054.68 J at 60 degrees (mainly Canadian), and 1,059.67 J at 39 degrees. A 1942 note suggests the term apparently arose in the United States and was later adopted in Britain.

The version on this site is the International Table Btu, about 1,055.06 J, which comes from the international steam table conferences that tied heat units to the joule. Joule's own 1850 experiments gave 772.692 foot-pounds of work per Btu, the number that first linked heat to mechanical effort.

Today the Btu survives in natural gas pricing (MMBtu means a million Btu), US building energy reporting, and equipment ratings in Btu per hour. One ton of air-conditioning is 12,000 Btu/h, or 3.52 kW. A single wooden kitchen match burning releases about one Btu.

1 British thermal unit = 1,055.055853 joules (approximately).

Sources: Wikipedia: British thermal unit; Wikipedia: James Prescott Joule

Related conversions

See all energy units.