1 BTU equals 1.05506 kJ. To convert BTU to kJ, multiply the value by 1.05506; divide by 1.05506 to convert back. Enter any number above and the result appears instantly — free and entirely in your browser.
How do you convert BTU to kJ?
The conversion formula is kJ = BTU × 1.05506. The conversion factor is fixed by definition, so the result is always exact.
BTU to kJ conversion table
| BTU | kJ |
|---|---|
| 1 BTU | 1.05506 kJ |
| 2 BTU | 2.11011 kJ |
| 5 BTU | 5.27528 kJ |
| 10 BTU | 10.5506 kJ |
| 100 BTU | 105.506 kJ |
| 1,000 BTU | 1,055.06 kJ |
What is BTU (BTU)?
The British thermal unit (BTU) is roughly the energy to heat one pound of water by 1 °F, about 1,055 joules. It rates heating, boilers and air conditioners, especially in the US.
What is kJ (kJ)?
The kilojoule (kJ) equals 1,000 joules. It is the SI energy unit on European food labels, usually shown next to kilocalories.
Why convert BTU to kJ?
Energy units come from different fields: joules and kilojoules in physics, kilocalories on food labels, kilowatt-hours on electricity bills, BTU in heating and air-conditioning. Converting between them is common for nutrition, utility bills and HVAC.
One kilocalorie (the food Calorie) equals exactly 4.184 kJ — which is why nutrition labels show both. One kilowatt-hour is 3.6 MJ, equal to about 3,412 BTU or 860 kcal (BIPM/ISO).
How to convert BTU to kJ
- Enter the value in BTU into the left field of the converter.
- Read the result in kJ instantly in the right field — it updates automatically.
- Use the swap button to reverse the direction (kJ to BTU).
The converter runs entirely in your browser: no uploads, no queue, no limits. You can even use it offline.