How to convert joules to British thermal units
BTU = J × 0.0009478171203Multiply the value in joules by 0.0009478171203. To go the other way, multiply by 1,055.055853 (or divide by 0.0009478171203).
A joule is smaller than a British thermal unit: it takes 1,055.055853 joules to make one British thermal unit.
Worked examples
- 1 joule1 J × 0.0009478171203 = 0.0009478171203 BTU
- 5 joules5 J × 0.0009478171203 = 0.004739085602 BTU
- 10 joules10 J × 0.0009478171203 = 0.009478171203 BTU
- 20 joules20 J × 0.0009478171203 = 0.01895634241 BTU
- 100 joules100 J × 0.0009478171203 = 0.09478171203 BTU
Joules to British thermal units conversion table
Values are calculated by the conversion engine and rounded to 8 significant figures.
| Joules (J) | British thermal units (BTU) |
|---|---|
| 0.1 J | 0.000094781712 BTU |
| 0.25 J | 0.00023695428 BTU |
| 0.5 J | 0.00047390856 BTU |
| 1 J | 0.00094781712 BTU |
| 2 J | 0.0018956342 BTU |
| 3 J | 0.0028434514 BTU |
| 4 J | 0.0037912685 BTU |
| 5 J | 0.0047390856 BTU |
| 6 J | 0.0056869027 BTU |
| 7 J | 0.0066347198 BTU |
| 8 J | 0.007582537 BTU |
| 9 J | 0.0085303541 BTU |
| 10 J | 0.0094781712 BTU |
| Joules (J) | British thermal units (BTU) |
|---|---|
| 12 J | 0.011373805 BTU |
| 15 J | 0.014217257 BTU |
| 20 J | 0.018956342 BTU |
| 25 J | 0.023695428 BTU |
| 30 J | 0.028434514 BTU |
| 40 J | 0.037912685 BTU |
| 50 J | 0.047390856 BTU |
| 75 J | 0.071086284 BTU |
| 100 J | 0.094781712 BTU |
| 250 J | 0.23695428 BTU |
| 500 J | 0.47390856 BTU |
| 1,000 J | 0.94781712 BTU |
About the units
Joule (J)
The SI unit of energy: the work done by a force of one newton over one metre, or one watt for one second. Lifting an apple by one metre takes about 1 J.
British thermal unit (BTU)
The International Table BTU, 1,055.05585262 J — roughly the energy to heat one pound of water by 1 °F. Furnace and AC capacities are rated in BTU (per hour). One British thermal unit equals 1,055.055853 joules (J).
Frequently asked questions
How many British thermal units are in one joule?
There are 0.0009478171203 British thermal units in one joule, and this value is exact by definition.
How do I convert joules to British thermal units?
Multiply the number of joules by 0.0009478171203. For example, 10 J × 0.0009478171203 = 0.009478171203 BTU.
How many joules are in one British thermal unit?
One British thermal unit equals 1,055.055853 joules. That is the reverse factor, 1 ÷ 0.0009478171203.
What is 10 joules in British thermal units?
10 J = 0.009478171203 BTU.
Is this J to BTU converter accurate?
Yes. Both units are defined exactly in terms of SI units, so the conversion factor is exact; results are shown to 12 significant figures by default and you can change precision in the converter. Calculations run in your browser using the same tested engine that generated this page.