How to convert international table btus to kilojoules
Apply the documented international table btus-to-kilojoules relationship below, keeping the full stored constant until the displayed result is rounded.
International Table BTUs × 1.055055853 = Kilojoules
For example, 10 Btu (IT) equals 10.55055853 kJ.
International Table BTUs to Kilojoules reference table
| International Table BTUs | Kilojoules |
|---|---|
| 1 Btu (IT) | 1.05505585 kJ |
| 5 Btu (IT) | 5.27527927 kJ |
| 10 Btu (IT) | 10.55055853 kJ |
| 25 Btu (IT) | 26.37639633 kJ |
| 50 Btu (IT) | 52.75279265 kJ |
| 100 Btu (IT) | 105.5055853 kJ |
Method and quality checks
- Calculation
- International Table BTUs × 1.055055853 = Kilojoules. The calculator keeps the stored factor through the operation and rounds only the displayed result to the selected or page-supported precision.
- Unit convention
- The named energy convention is used exactly as labelled. Small calories, food Calories, and alternate BTU definitions must not be mixed.
- Input validation
- Finite numeric inputs are accepted. Results outside the supported numeric range are rejected instead of being displayed as valid measurements.
- Reasonableness check
- 10 Btu (IT) produces 10.55055853 kJ. Check the direction and approximate scale before relying on a more precise displayed value.
Deeper method: How significant figures work.
This converter uses the International Table BTU
British thermal unit definitions vary slightly. This page uses the International Table British thermal unit, where 1 Btu (IT) is approximately 1.055055853 kilojoules; a thermochemical BTU uses a different factor.
- Look for Btu (IT) or Btu (th) in a technical specification before converting.
- BTU is energy, while BTU per hour is a rate of power and needs a different conversion.
- Heating-system ratings may describe input, output, or capacity, so preserve the original label.
Reference: NIST energy conversion factors.