Convert joules to British thermal units
Converting joules to British thermal units is a common energy task, whether you are checking a recipe, a spec sheet, a travel distance or a homework problem. Since 1 J equals 0.000947817 BTU, the math is a single multiplication — and this page does it for you instantly, with the formula, a table of common values and answers to the questions people ask most.
Exact factor
How to convert joules to British thermal units
To convert joules to British thermal units, multiply the number of joules by 0.000947817. For example, 10 J × 0.000947817 = 0.00947817 BTU.
BTU = J × 0.000947817
- Write down the value in joules you want to convert.
- Multiply it by 0.000947817 (the exact J→BTU factor).
- The result is your value in British thermal units. Check it below with the converter or the table.
Conversion table
Common values of joules and their equivalents in British thermal units:
| J | BTU |
|---|---|
| 1 | 0.000947817 |
| 2 | 0.00189563 |
| 3 | 0.00284345 |
| 4 | 0.00379127 |
| 5 | 0.00473909 |
| 10 | 0.00947817 |
| 20 | 0.0189563 |
| 25 | 0.0236954 |
| 50 | 0.0473909 |
| 100 | 0.0947817 |
| 250 | 0.236954 |
| 500 | 0.473909 |
About these units
Joule (J). The joule is the SI unit of energy: the work done by one newton acting over one meter. Food labels in most countries, physics and engineering use joules.
British Thermal Unit (BTU). A British thermal unit is the energy to raise one pound of water by 1 °F, about 1,055 joules. Air conditioners, heaters and grills in the US are rated in BTU.
Frequently asked questions
How do I convert joules to British thermal units?
To convert joules to British thermal units, multiply the number of joules by 0.000947817. For example, 10 J × 0.000947817 = 0.00947817 BTU. Or skip the math: type the value into the converter at the top of this page and the result updates instantly.
How many British thermal units are in 1 joule?
1 J = 0.000947817 BTU. That is the fixed relationship used by this converter and by international standards.
How many joules are in 1 british thermal unit?
1 BTU = 1,055.06 J. If you are converting in the opposite direction, use our British Thermal Unit to Joule converter for the dedicated table and FAQ.
Is the joules to British thermal units conversion exact?
Yes. Both units are defined by international agreement, so the factor of 0.000947817 is exact. Displayed results are rounded to 6 significant digits only for readability.
What is joule used for?
The joule is the SI unit of energy: the work done by one newton acting over one meter. Food labels in most countries, physics and engineering use joules.