The British thermal unit (BTU) is the energy needed to raise one pound of water by one degree Fahrenheit, widely used for heating and air-conditioning ratings.
Btu to Kilojoules
Convert British thermal unit (BTU) to Kilojoule (kJ) instantly with an exact formula, conversion table, and FAQ.
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Convert btu (BTU) to kilojoules (kJ) instantly with formula, conversion table, and FAQ.
Context values
Some unit families need one extra value for a physically accurate result.
A kilojoule (kJ) equals 1,000 joules and is commonly used on nutrition labels outside the United States.
kJ = BTU × 1.055055853
Results update instantly for Btu to Kilojoules conversions.
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Formula
kJ = BTU × 1.055055853
BTU = kJ × 0.9478171203
Conversion table
| 1 BTU | 1.055056 kJ |
| 5 BTU | 5.275279 kJ |
| 10 BTU | 10.550559 kJ |
| 20 BTU | 21.101117 kJ |
| 50 BTU | 52.752793 kJ |
| 100 BTU | 105.505585 kJ |
| 500 BTU | 527.527926 kJ |
| 1000 BTU | 1055.055853 kJ |
Related conversions
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How the formula works
Both british thermal unit and kilojoule measure the same physical quantity, so converting between them is a single multiplication. Multiply a value in btu by 1.055055853 to get kilojoules. To reverse the conversion, multiply a kilojoule value by 0.9478171203 to get back to btu.
Frequently asked questions
What is British thermal unit (BTU)?
The British thermal unit (BTU) is the energy needed to raise one pound of water by one degree Fahrenheit, widely used for heating and air-conditioning ratings.
What is Kilojoule (kJ)?
A kilojoule (kJ) equals 1,000 joules and is commonly used on nutrition labels outside the United States.
How do I convert btu to kilojoules?
Multiply the british thermal unit value by 1.055055853 to get the equivalent in kilojoules. For example, 5 BTU × 1.055055853 = 5.275279 kJ.
Is this conversion exact?
Yes. Both units are defined against the SI base unit for this dimension, so the factor 1.055055853 is an exact, non-rounded value.
Can I convert kilojoules back to btu?
Yes. Divide the kilojoule value by 1.055055853, or multiply it by 0.9478171203, to get btu.
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About converting btu to kilojoules
The British thermal unit (BTU) is the energy needed to raise one pound of water by one degree Fahrenheit, widely used for heating and air-conditioning ratings. A kilojoule (kJ) equals 1,000 joules and is commonly used on nutrition labels outside the United States.
Use this calculator to move between btu and kilojoules accurately for homework, engineering, billing, or everyday energy calculations. The Universal Converter uses exact unit factors, so results stay consistent across the site.