How to Convert Kilojoules to British thermal units (kJ to BTU)
Energy conversions link food labels in kJ and kcal, SP Group bills in kWh and air-conditioner capacity in BTU. This guide shows how to convert kilojoules into british thermal units by hand, with examples and a quick-reference table.
The conversion
To convert kilojoules to british thermal units, multiply the value by 0.9478171227. To go the other way, divide by the same number (or multiply by 1.05505585). For a quick estimate, multiply by about 0.95.
British thermal units = kilojoules × 0.9478171227
Worked examples
- 3 kJ = 2.8435 BTU
- 12.5 kJ = 11.8477 BTU
- 75 kJ = 71.0863 BTU
Kilojoules to British thermal units table
| Kilojoules | British thermal units |
|---|---|
| 1 kJ | 0.947817 BTU |
| 2 kJ | 1.8956 BTU |
| 5 kJ | 4.7391 BTU |
| 10 kJ | 9.4782 BTU |
| 20 kJ | 18.9563 BTU |
| 25 kJ | 23.6954 BTU |
| 50 kJ | 47.3909 BTU |
| 100 kJ | 94.7817 BTU |
| 250 kJ | 236.9543 BTU |
| 500 kJ | 473.9086 BTU |
| 1,000 kJ | 947.8171 BTU |
Common questions
Is kJ to BTU exact?
The factors used here are the internationally defined values where they exist; results are rounded for display only.
How do I convert back?
Use the British thermal units to Kilojoules converter.
Mistakes to avoid
Dropping the units
A bare number without a unit is easy to misread later. Always write the unit with the result.
Forgetting squared and cubed units
Area and volume factors are the length factor squared or cubed, so 1 m² is about 10.76 sq ft, not 3.28.
Mixing similar-sounding units
US and imperial gallons, pints and tons are different sizes, and decimal kilobytes differ from binary kibibytes.
Background
Unit conversion is simply multiplication by a fixed ratio. The ratio between two units of the same quantity never changes, so once you know it you can convert any value in either direction.
Writing the units next to every number while you work is the simplest way to avoid mistakes. If the units do not cancel to leave the one you want, the calculation is set up wrongly.
For everyday use, three or four significant figures are usually enough. Engineering, science and trade documents may need more, and rounding should happen only at the end of a calculation.
For any value, use the Kilojoules to British thermal units Converter or browse all energy converters.
Run your own numbers: Kilojoules to British thermal units Converter