BTUs to Kilojoules Converter
Enter the energy in btus below to convert it to kilojoules.
Convert BTUs to Kilojoules
Enter a value in btus (BTU) to convert to kilojoules (kJ).
British Thermal Unit to Kilojoule Conversion Table
Table showing various british thermal unit measurements converted to kilojoules. Click any preset value or arrow to load it into the converter.
| BTUs (BTU) | Kilojoules (kJ) |
|---|---|
| 1 BTU | 1.0550559 kJ |
| 2 BTU | 2.1101117 kJ |
| 2.5 BTU | 2.6376396 kJ |
| 5 BTU | 5.2752793 kJ |
| 10 BTU | 10.5505585 kJ |
| 15 BTU | 15.8258378 kJ |
| 20 BTU | 21.1011171 kJ |
| 25 BTU | 26.3763963 kJ |
| 30 BTU | 31.6516756 kJ |
| 50 BTU | 52.7527926 kJ |
How to Convert BTUs to Kilojoules
To convert btus to kilojoules, multiply the energy by the following conversion ratio: 1.0550559 kilojoules/british thermal unit.
Since one british thermal unit is equal to 1.0550559 kilojoules, you can use this simple formula to convert:
The energy in kilojoules is equal to the energy in btus multiplied by 1.0550559.
For example, here's how to convert 5 btus to kilojoules using the formula above.
How Many Kilojoules Are in a British Thermal Unit?
There are 1.0550559 kilojoules in a british thermal unit, which is why we use this value in the formula above.
Our british thermal unit to kilojoule calculator automatically converts your energy measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.
BTUs and kilojoules are both units used to measure energy. Keep reading to learn more about each unit.
What Is a British Thermal Unit?
A british thermal unit is a unit of energy equal to 1,055.0558526 joules (J), the base unit for energy. Thermal energy unit equal to 1,055.056 Joules. [1]
The british thermal unit is classified as a US customary and imperial unit of energy. BTUs can be abbreviated as BTU; for example, 1 british thermal unit can be written as 1 BTU.
When working with btus (BTU) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.
In practice, btus (BTU) are widely used across large-scale industrial, bulk, and macro-level energy specifications within US customary and imperial workflows, engineering documentation, and technical data sheets.
What Is a Kilojoule?
A kilojoule is a unit of energy equal to 1,000 joules (J), the base unit for energy. Equal to 1,000 Joules. [2]
The kilojoule is classified as a metric and SI-compatible unit of energy. Kilojoules can be abbreviated as kJ; for example, 1 kilojoule can be written as 1 kJ.
In the metric system, "kilo" is the standard SI prefix for thousands, or 10³. This makes the kilojoule (kJ) a convenient decimal multiple of the joule (J).
In practice, kilojoules (kJ) are widely used across large-scale industrial, bulk, and macro-level energy specifications within SI metric workflows, engineering documentation, and technical data sheets.
When converting energy between btus (BTU) and kilojoules (kJ), keep full floating-point precision (1 BTU = 1.0550559 kJ; 1 kJ = 0.9478171 BTU) during intermediate calculations and round only the final kilojoule figure to match your instrument tolerance.
More British Thermal Unit & Kilojoule Conversions
Need to calculate in the opposite direction? Use our kilojoules to btus calculator to switch your starting unit immediately. You can also explore related tools such as converting kilojoules to btus, converting joules to kilojoules, or converting kilocalories to kilojoules.
Frequently Asked Questions
References
- [1]NIST CODATA StandardNIST CODATA (CODATA Energy & Thermodynamic Constants)·Energy Metrology Standard — BTUs (BTU) to Kilojoules (kJ)
- [2]NIST SP 811 SpecificationNIST SP 811 (NIST SP 811 App. B.9 (Energy, Work & Heat))·Unit Specifications: British Thermal Unit (BTU) (BTU) & Kilojoule (kJ)
- [3]BIPM ReferenceBIPM (Derived SI Unit: Joule (J))·Conversion Factors & Mathematical Basis (BTU to kJ)