BTU to kW converter
Convert heater and air conditioner output between BTU an hour and kilowatts.
Uses the conversion factor published by NIST: one BTU an hour is 0.2930711 watts.
Show the workings
| Step | Sum | Answer |
|---|---|---|
| Multiply by the watts in one BTU per hour, then divide by 1,000 | 10,000 BTU/h × 0.2930711 ÷ 1,000 | 2.931 kW |
Where the figures come from
- One British thermal unit (IT) per hour, in watts: 0.2930711 watts. Source: NIST Guide to the SI, Appendix B.8: Factors for Units Listed Alphabetically. Checked 13 November 2026.
The sum
BTU is short for British thermal unit. Heaters, radiators and air conditioners are often rated in BTU an hour, which is a measure of power, like kilowatts.
One BTU an hour is 0.2930711 watts. So multiply BTU an hour by 0.2930711 and divide by 1,000 to get kilowatts. To go the other way, multiply kilowatts by 1,000 and divide by 0.2930711.
| BTU an hour | Kilowatts |
|---|---|
| 5,000 | 1.47 kW |
| 7,000 | 2.05 kW |
| 9,000 | 2.64 kW |
| 12,000 | 3.52 kW |
| 18,000 | 5.28 kW |
| 24,000 | 7.03 kW |
This is the heat or cooling an appliance gives out. It is not always the electricity it uses: an air conditioner or heat pump moves more heat than the electricity it draws. For running costs, use the electrical power on the rating plate in the running cost calculator.