Kilowatt-Hours to BTU

Kilowatt-hours and BTU

A kilowatt-hour is 1,000 watts for one hour: exactly 3.6 million joules. Electricity bills, EV batteries and appliance energy labels use kWh.

The International Table BTU is 1,055.05585262 joules, about the energy to warm one pound of water by 1 °F. Furnaces, boilers, grills and natural gas in the US are rated in BTU.

Worked example

Convert 10 kWh: 10 × 3,412.141633 = 34,121.41633, so 10 kilowatt-hours is 34,121.41633 BTU. Likewise 50 kWh = 170,607.0817 BTU.

Estimating in your head

Multiply by 3,400 for a quick figure; it is off by about 0.4%. For 10 kWh that gives 34,000 BTU, against 34,121.4 exactly.

Going the other way

To convert BTU to kilowatt-hours, divide by 3,412.141633 (or multiply by 0.000293071070172). The swap button between the boxes opens that page.

BTU = kWh × 3,412.141633

1 kWh = 3,600,000 J and 1 BTU = 1,055.05585262 J, both by definition, so the factor is their ratio: 3,412.141633 (rounded here; the page uses the full value). Results drop binary floating-point noise beyond 15 significant digits and display at the precision you choose (6 significant figures by default). Copy result copies the full value.