British thermal units to kilojoules
Type a value in British thermal units to see it in kilojoules straight away, or type in the second box to convert back.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Type the value in the British thermal units box.
- Read the result in kilojoules as you type, and pick the precision you need.
- Swap the direction to convert back, or copy the result.
How it is calculated
kJ = BTU × 1.055055853
Multiply the value in British thermal units by 1.055055853 to get kilojoules.
Example
To convert 25 BTU to kilojoules: 25 × 1.055055853 = 26.3764 kJ.
Conversion table
| British thermal units (BTU) | Kilojoules (kJ) |
|---|---|
| 1 | 1.05506 |
| 2 | 2.11011 |
| 3 | 3.16517 |
| 5 | 5.27528 |
| 10 | 10.5506 |
| 20 | 21.1011 |
| 25 | 26.3764 |
| 50 | 52.7528 |
| 100 | 105.506 |
| 250 | 263.764 |
| 500 | 527.528 |
| 1,000 | 1,055.06 |
About the units
- British thermal unit
- The imperial unit of heat, using the International Table definition of exactly 1055.05585262 joules. Seen in air conditioner and heater ratings.
- Kilojoule
- Exactly 1000 joules. It appears on food labels next to the calorie figure.
Limits and caveats
- Results are rounded for display and computed with the browser's floating point precision (about 15 significant digits).
- Both unit factors are exact by their official definitions.
Questions about this tool
How many kilojoules are in one British thermal unit?
1 BTU = 1.05506 kJ exactly.
How do I convert British thermal units to kilojoules?
Use kJ = BTU × 1.055055853. For example, 25 BTU = 26.3764 kJ.
How many British thermal units are in one kilojoule?
1 kJ = 0.947817 BTU.
Which calorie do these converters use?
The thermochemical calorie, exactly 4.184 joules, the factor many countries use to turn kcal into kJ on food labels. The International Table calorie is 4.1868 joules, less than 0.07% larger.
What is the difference between kW and kWh?
A kilowatt is a unit of power, the rate of using energy, while a kilowatt-hour is an amount of energy. A 2 kW heater running for three hours uses 6 kWh.