British Thermal Unit to Kilojoule Converter
One British Thermal Unit equals 1.055055853 Kilojoule (1 BTU = 1.055055853 kJ). Multiply a British Thermal Unit value by 1.055055853 to get the equivalent in Kilojoule. Use the calculator above for instant results, or follow the formula, worked examples, and reference table below.
Formula
kJ = BTU × 1.055055853
Multiply the British Thermal Unit value by 1.055055853 to get the equivalent value in Kilojoule.
Example Conversions
1 British Thermal Unit (BTU)
1.055055853 Kilojoule (kJ)
5 British Thermal Unit (BTU)
5.275279263 Kilojoule (kJ)
10 British Thermal Unit (BTU)
10.55055853 Kilojoule (kJ)
25 British Thermal Unit (BTU)
26.37639632 Kilojoule (kJ)
100 British Thermal Unit (BTU)
105.5055853 Kilojoule (kJ)
Conversion Table
| British Thermal Unit (BTU) | Kilojoule (kJ) |
|---|---|
| 0.1 | 0.1055055853 |
| 0.5 | 0.5275279263 |
| 1 | 1.055055853 |
| 2 | 2.110111705 |
| 5 | 5.275279263 |
| 10 | 10.55055853 |
| 25 | 26.37639632 |
| 50 | 52.75279263 |
| 100 | 105.5055853 |
| 250 | 263.7639632 |
| 500 | 527.5279263 |
| 1000 | 1055.055853 |
How to Convert Manually
Use these steps to convert British Thermal Unit values to Kilojoule without the calculator.
- Write down the value in British Thermal Unit (BTU) that you want to convert.
- Multiply that value by 1.055055853.
- For example, 10 British Thermal Unit × 1.055055853 = 10.55055853 Kilojoule.
- Label the result as Kilojoule (kJ).
Relative Size Comparison
This chart shows the visual difference in size between exactly one British Thermal Unit and one Kilojoule.
About British Thermal Unit and Kilojoule
The British thermal unit is about 1,055.06 joules — the heat to raise one pound of water by 1 °F. US heating and cooling equipment is rated in BTU per hour. The kilojoule is 1,000 joules. Food energy in Australia, Europe, and most metric countries is labeled in kilojoules alongside or instead of calories. One British Thermal Unit equals 1.055055853 Kilojoule (1 BTU = 1.055055853 kJ). British Thermal Unit to Kilojoule conversion comes up most often in air conditioner and furnace ratings in the US and in US natural gas appliance specs, typically when figures need restating for food labels outside the US.
Precision and Rounding: Energy factors mix exact definitions (1 kWh = 3,600,000 J; 1 cal = 4.184 J thermochemical) with measured conventions (1 BTU ≈ 1,055.056 J). Nutrition and utility bills round to whole units; engineering heat calculations should keep the full factor until the final step.
Conversion factors per NIST Special Publication 811 and the BIPM SI Brochure (9th edition) (reference).
Worked Example
15 British Thermal Unit equals 15.82583779 Kilojoule.
15 BTU × 1.055055853 = 15.82583779 kJ
FAQ
How do I convert British Thermal Unit to Kilojoule?
Multiply the British Thermal Unit value by 1.055055853 to get the equivalent value in Kilojoule.
What is the formula for British Thermal Unit to Kilojoule?
The formula is kJ = BTU × 1.055055853.
How many Kilojoule are in 1 British Thermal Unit?
1 British Thermal Unit equals 1.055055853 Kilojoule.
Can I convert Kilojoule back to British Thermal Unit?
Yes. 1 Kilojoule equals 0.9478171203 British Thermal Unit, and the related converter can reverse the calculation.
What are common names for British Thermal Unit and Kilojoule?
British Thermal Unit is shown as BTU and may also be searched as btu, british thermal unit. Kilojoule is shown as kJ and may also be searched as kilojoule, kilojoules.
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