BTU to Joules Converter

One british thermal unit equals 1055.0559 joules (J). To convert british thermal units to joules, multiply by 1055.0559; to go back the other way, multiply by 0.00094781712 instead.

The converter above does it as you type and shows the working underneath, so you can check the arithmetic rather than take the number on trust.

What british thermal units and joules actually measure

British thermal unit (BTU) — A British thermal unit raises a pound of water by one degree Fahrenheit — about 1,055 joules. Heating, air conditioning and gas in the US.

Joule (J) — The joule is the SI unit of energy — one watt for one second. Physics, mechanical work and food energy in most of the world.

BTU to Joules conversion table

The most common values, worked out in advance. Anything not listed can be typed straight into the converter.

How to convert british thermal units to joules by hand

Multiply the number of british thermal units by 1055.0559.

For example, 25 BTU × 1055.0559 = 26376.396 J.

Going the other way, divide by 1055.0559 — or multiply by 0.00094781712, which is the same thing and easier to do in your head.

Everything runs in your browser

There is no server involved in the calculation. The numbers you type never leave your device, nothing is logged, and the page keeps working with no connection once it has loaded. That is not a marketing line — it is simply how the tool is built, because a calculation like this has no reason to touch a network.