Joules to BTU Converter

One joule equals 0.00094781712 british thermal units (BTU). To convert joules to british thermal units, multiply by 0.00094781712; to go back the other way, multiply by 1055.0559 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 joules and british thermal units actually measure

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.

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.

Joules to BTU conversion table

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

How to convert joules to british thermal units by hand

Multiply the number of joules by 0.00094781712.

For example, 25 J × 0.00094781712 = 0.023695428 BTU.

Going the other way, divide by 0.00094781712 — or multiply by 1055.0559, 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.