kW to BTU/h Converter
Convert kilowatts to BTU per hour — the heating and cooling capacity conversion. Results update as you type; exact factors shown.
One kilowatt is 3,412.1416 BTU per hour — see the exact factor, not a rounded rule of thumb.
How the kw to btu/h converter works
Power converts through the watt. Mechanical horsepower is 550 ft·lbf/s = 745.6999 W; metric horsepower (PS, used in European car specs) is 735.4988 W. Air-conditioner capacities are quoted in kW, BTU/h (1 W = 3.412 BTU/h) or tons of refrigeration (3.517 kW).
Australia is fully metric under the National Measurement Act 1960; imperial units appear only in trade with the US and in older documents.
Common power conversions
| From | To | Units |
|---|---|---|
| 1 kW | 3,412.1416 BTU/h | kilowatt to BTU per hour |
| 1.5 kW | 5,118.2125 BTU/h | kilowatts to BTU per hour |
| 2 kW | 6,824.2833 BTU/h | kilowatts to BTU per hour |
| 2.5 kW | 8,530.3541 BTU/h | kilowatts to BTU per hour |
| 3.5 kW | 11,942.4957 BTU/h | kilowatts to BTU per hour |
| 5 kW | 17,060.7082 BTU/h | kilowatts to BTU per hour |
| 6 kW | 20,472.8498 BTU/h | kilowatts to BTU per hour |
| 7 kW | 23,884.9914 BTU/h | kilowatts to BTU per hour |
| 8 kW | 27,297.1331 BTU/h | kilowatts to BTU per hour |
| 10 kW | 34,121.4164 BTU/h | kilowatts to BTU per hour |
| 12 kW | 40,945.6996 BTU/h | kilowatts to BTU per hour |
| 20 kW | 68,242.8327 BTU/h | kilowatts to BTU per hour |
Units in this converter and their exact factors
| Unit | Symbol | One unit in watts |
|---|---|---|
| watt | W | 1 watt |
| kilowatt | kW | 1,000 watt |
| megawatt | MW | 1,000,000 watt |
| horsepower (mechanical) | hp | 745.6998715823 watt |
| metric horsepower (PS) | PS | 735.49875 watt |
| BTU per hour | BTU/h | 0.29307107 watt |
| ton of refrigeration | TR | 3,516.8528421 watt |
FAQFrequently asked questions about power conversion
How many BTU/h in a kW?
3,412.14.
What is a 3.5 kW air conditioner in BTU?
About 12,000 BTU/h — one ton of refrigeration.
Why two different ratings?
Metric countries rate air conditioners in kW; the US rates them in BTU per hour. They describe the same capacity.
What size unit do I need?
Very roughly 0.15 kW per square metre for a well-insulated room, but a proper heat-load calculation is worth doing.
What is a ton of refrigeration?
3.517 kW — the rate that would freeze one short ton of water in 24 hours.
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Measurement Institute (NMI) — Australia's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.