Kilojoules to BTU Converter
Convert kilojoules to British thermal units — 1.055 kJ to the BTU. Results update as you type; exact factors shown.
One kilojoule is 0.9478 British thermal units — see the exact factor, not a rounded rule of thumb.
How the kilojoules to btu 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 kJ | 0.9478 BTU | kilojoule to British thermal units |
| 5 kJ | 4.7391 BTU | kilojoules to British thermal units |
| 10 kJ | 9.4782 BTU | kilojoules to British thermal units |
| 50 kJ | 47.3909 BTU | kilojoules to British thermal units |
| 100 kJ | 94.7817 BTU | kilojoules to British thermal units |
| 105.5 kJ | 99.9947 BTU | kilojoules to British thermal units |
| 500 kJ | 473.9086 BTU | kilojoules to British thermal units |
| 1,000 kJ | 947.8171 BTU | kilojoules to British thermal units |
| 5,000 kJ | 4,739.0856 BTU | kilojoules to British thermal units |
| 10,000 kJ | 9,478.1712 BTU | kilojoules to British thermal units |
| 50,000 kJ | 47,390.856 BTU | kilojoules to British thermal units |
| 100,000 kJ | 94,781.712 BTU | kilojoules to British thermal units |
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 kilojoules in a BTU?
1.055 kJ.
What is 1,000 kJ?
948 BTU.
Where is the BTU used?
US heating and cooling, and gas billing. Almost everywhere else uses joules or kilowatt-hours.
What is a BTU physically?
The heat to raise one pound of water by one degree Fahrenheit — the imperial analogue of the calorie.
What is 105.5 kJ?
100 BTU.
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.