Joules to British Thermal Units Converter
1 joule ≈ 0.00094781712 British thermal units
Several BTU definitions exist. This converter uses the International Table BTU, the one used by HVAC equipment ratings.
1 joule equals 0.000947817 British thermal units
How to convert joules to British thermal units
Calories here are thermochemical (4.184 J), while BTU uses the International Table definition. A kilowatt-hour is energy (3.6 MJ), not power; a food Calorie is a kilocalorie.
BTU = J ÷ 1055.055853One British thermal unit corresponds to 1055.055853 joules, so divide by that figure. Displayed constants may be rounded; the converter uses the stored factor before rounding the result.
0.00947817 BTU ≈ 10 ÷ 1055.055853Several BTU definitions exist. This converter uses the International Table BTU, the one used by HVAC equipment ratings.
Joules to British thermal units conversion table
Common values in joules, converted to British thermal units.
| Joules (J) | British thermal units (BTU) |
|---|---|
| 1 | 0.00094781712 |
| 2 | 0.0018956342 |
| 3 | 0.0028434514 |
| 4 | 0.0037912685 |
| 5 | 0.0047390856 |
| 10 | 0.0094781712 |
| 20 | 0.018956342 |
| 25 | 0.023695428 |
| 50 | 0.047390856 |
| 100 | 0.094781712 |
| 250 | 0.23695428 |
| 500 | 0.47390856 |
| 1,000 | 0.94781712 |
About these units
jouleJ
The SI derived unit of energy: one newton acting through one metre.
British thermal unitBTU
The International Table BTU: 1,055.05585262 joules. The US heating and cooling unit.
Reference: NIST Special Publication 811.
Sources and precision
Table results are rounded to 8 significant digits; formula constants may be rounded to 10. Worked example answers use 6 significant digits. The converter starts at 6 significant digits and lets you change display precision. Calculations use the stored factors without intermediate rounding. Exact unit definitions do not make an input measurement more precise; conventional and measured factors follow the assumptions stated here.