BTU to Joules Converter
Convert British thermal units to joules — one BTU is 1,055.06 J. Results update as you type; exact factors shown.
One British thermal unit is 1,055.0559 joules — see the exact factor, not a rounded rule of thumb.
How the btu to joules converter works
Energy converts through the joule. A thermochemical calorie is exactly 4.184 J, so a food Calorie (kcal) is 4.184 kJ. A kilowatt-hour is exactly 3.6 MJ. A BTU is 1,055.056 J and a US therm is 100,000 BTU.
Australia is fully metric under the National Measurement Act 1960; imperial units appear only in trade with the US and in older documents.
Common energy conversions
| From | To | Units |
|---|---|---|
| 1 BTU | 1,055.0559 J | British thermal unit to joules |
| 5 BTU | 5,275.2793 J | British thermal units to joules |
| 10 BTU | 10,550.5585 J | British thermal units to joules |
| 50 BTU | 52,752.7926 J | British thermal units to joules |
| 100 BTU | 105,505.5853 J | British thermal units to joules |
| 500 BTU | 527,527.9263 J | British thermal units to joules |
| 1,000 BTU | 1,055,055.8526 J | British thermal units to joules |
| 3,412 BTU | 3,599,850.5691 J | British thermal units to joules |
| 5,000 BTU | 5,275,279.2631 J | British thermal units to joules |
| 10,000 BTU | 10,550,558.5262 J | British thermal units to joules |
| 100,000 BTU | 105,505,585.262 J | British thermal units to joules |
| 1,000,000 BTU | 1,055,055,852.62 J | British thermal units to joules |
Units in this converter and their exact factors
| Unit | Symbol | One unit in joules |
|---|---|---|
| joule | J | 1 joule |
| kilojoule | kJ | 1,000 joule |
| megajoule | MJ | 1,000,000 joule |
| calorie (thermochemical) | cal | 4.184 joule |
| kilocalorie (food Calorie) | kcal | 4,184 joule |
| watt-hour | Wh | 3,600 joule |
| kilowatt-hour | kWh | 3,600,000 joule |
| British thermal unit | BTU | 1,055.05585262 joule |
| therm (US) | thm | 105,505,585.262 joule |
| foot-pound | ft·lb | 1.3558179483 joule |
FAQFrequently asked questions about energy conversion
How many joules in a BTU?
1,055.06 J for the international table BTU.
What is a BTU?
The energy to raise one pound of water by one degree Fahrenheit.
What is 3,412 BTU?
One kilowatt-hour — 3.6 MJ.
Where is the BTU used?
US heating and air conditioning, and the gas industry. Everywhere else uses joules or kilowatt-hours.
What is 100,000 BTU?
One therm, which is 105.5 MJ.
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Measurement Institute (NMI) — Australia's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.