About the BTU to kWh Converter
A BTU, or British thermal unit, is the heat needed to warm one pound of water by one degree Fahrenheit, and it is still the energy unit on gas bills, boilers, furnaces and heating guides in the United States. Electricity is sold in kilowatt-hours. This converter turns BTU into kWh so you can compare a gas furnace with an electric heater, or check an energy label. It uses the International Table BTU, where one BTU is 1,055.05585262 joules, and one kilowatt-hour is exactly 3,600,000 joules. Type a number and the answer appears at once, with watt-hours, joules, kilojoules, calories and other units listed beneath it. It runs in your browser.
Updated October 2026
How to use the BTU to kWh Converter
- 1Type the amount of energy in BTU.
- 2Read the result in kilowatt-hours at the top.
- 3Look at the rows below for watt-hours, joules, kilojoules and more.
- 4Press Copy to copy the sentence, for example 10000 BTU = 2.930710702 kWh.
- 5Change the number to try another amount.
The formula
kWh = BTU × 0.000293071070172. The factor comes from dividing one BTU in joules, 1,055.05585262, by the 3,600,000 joules in a kilowatt-hour.
Going back, BTU = kWh × 3,412.14163313.
Where BTU and kWh meet
- Heating: a furnace labelled 80,000 BTU/h that runs for one hour delivers 80,000 BTU, which is 23.4 kWh of heat.
- Gas bills: a therm is 100,000 BTU, so a gas bill in therms is easy to turn into kWh.
- Heat pumps: their output in BTU/h and input in kW can be compared once both are in the same unit.
- Appliance labels: older labels list BTU, newer ones list kWh per year.
- Solar and storage: heat energy in BTU can be compared with battery capacity in kWh.
Common mistakes
Mixing energy and power is the most common error. BTU and kWh are energy. BTU per hour and kW are power. A 3.5 kW heater running for two hours uses 7 kWh, or about 23,900 BTU.
Efficiency matters too. A furnace that is 90 percent efficient turns 90 percent of the fuel's BTU into heat in the room, so the fuel energy you pay for is larger than the heat you get.
Phone and computer
The number box and results stack on a phone and sit side by side on a computer. Results update as you type. Heating and cooling labels often mix BTU, watts and kilowatt-hours. Reverse this calculation with the kWh to BTU Converter, convert a power rating with the BTU/h to Watts Converter, and put a price on the energy with the Electricity Cost Calculator.
Features
- Uses the International Table BTU (1,055.05585262 J)
- Exact kilowatt-hour definition (3.6 million joules)
- Shows eight other energy units at the same time
- Answers up to ten significant digits
- Copy result button
- Works offline in your browser, nothing is sent
Frequently asked questions
How many kWh are in one BTU?
One BTU is about 0.000293071 kWh. The other way round, one kWh is about 3,412.14 BTU.
How do I convert BTU to kWh by hand?
Multiply the BTU figure by 0.000293071. For example 10,000 BTU times 0.000293071 gives about 2.93 kWh.
Is BTU per hour the same as BTU?
No. BTU measures an amount of energy, while BTU per hour measures power, the rate of using energy. A 12,000 BTU/h air conditioner uses 12,000 BTU in one hour, which is about 3.52 kWh of heat moved. Use the BTU/h to Watts converter for power.
Which BTU does the converter use?
The International Table BTU, which is the common one in engineering and in the US. Other definitions, such as the thermochemical BTU, differ by less than 0.1 percent.
Why compare BTU with kWh?
Gas and oil are sold by heat content in BTU, therms or MMBtu, and electricity by kWh. Converting both to kWh lets you compare running costs: one therm is 100,000 BTU, about 29.3 kWh.
Can I use negative numbers?
Yes, the maths is the same, which is useful for heat lost or removed. Zero gives zero.
Is the result exact?
The kWh is exact by definition and the BTU value is the International Table figure, so the answer is as accurate as that definition. It is shown to ten significant digits.