British Thermal Units to Kilojoules Converter

One British Thermal Unit equals 1.055055853 Kilojoules (1 BTU = 1.055055853 kJ). Multiply a British Thermal Unit value by 1.055055853 to get the equivalent in Kilojoules. Enter your value in the calculator above. The formula and examples below show how to calculate it by hand.

Formula

kJ = BTU × 1.055055853

Multiply the British Thermal Unit value by 1.055055853 to get the equivalent value in Kilojoules.

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

Common conversion values from British Thermal Unit to Kilojoule
British Thermal Unit (BTU)Kilojoule (kJ)
0.10.1055055853
0.50.5275279263
11.055055853
22.110111705
55.275279263
1010.55055853
2526.37639632
5052.75279263
100105.5055853
250263.7639632
500527.5279263
10001055.055853

How to Convert Manually

Use these steps to convert British Thermal Unit values to Kilojoule without the calculator.

  1. Write down the value in British Thermal Unit (BTU) that you want to convert.
  2. Multiply that value by 1.055055853.
  3. For example, 10 British Thermal Units × 1.055055853 = 10.55055853 Kilojoules.
  4. Label the result as Kilojoule (kJ).

Relative Size Comparison

1 British Thermal Unit
1 BTU
1 Kilojoule0.9478171203 British Thermal Units
1 kJ

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 Kilojoules (1 BTU = 1.055055853 kJ). British Thermal Unit is used in air conditioner and furnace ratings in the US and in US natural gas appliance specs. Kilojoule is used in 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

15British Thermal Units equals15.82583779Kilojoules.

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 Kilojoules.

What is the formula for British Thermal Unit to Kilojoule?

The formula is kJ = BTU × 1.055055853.

How many Kilojoules are in 1 British Thermal Unit?

1 British Thermal Unit equals 1.055055853 Kilojoules.

Can I convert Kilojoule back to British Thermal Unit?

Yes. 1 Kilojoule equals 0.9478171203 British Thermal Units, 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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