BTU/hr to Watts Converter
BTU per hour is the traditional US unit for heating and cooling capacity. One BTU is the energy needed to raise one pound of water by 1°F. One watt is one joule per second. The...
Formula
Source: Engineering Toolbox, ASHRAE | Last reviewed: June 8, 2026
Examples
1 BTU/hr
= 0.293 W
1 BTU/hr = 0.293 W
3412 BTU/hr
= 1000 W
3,412 BTU/hr = 1 kW (rule of thumb)
12000 BTU/hr
= 3517 W
1 ton of refrigeration = 12,000 BTU/hr = 3.517 kW
100000 BTU/hr
= 29307 W
Typical residential furnace (100,000 BTU/hr)
Quick Reference Table
| BTU/hr | Watts |
|---|---|
| 1 | 0.293 |
| 1000 | 293.1 |
| 3412 | 1000 |
| 12000 | 3517 |
| 24000 | 7034 |
| 36000 | 10551 |
| 100000 | 29307 |
Where is this used?
Energy efficiency calculations: translating thermal loads to electrical power requirements.
Building energy modeling and LEED documentation requiring SI units.
Frequently Asked Questions
Why is 3,412 BTU/hr = 1 kW important?
3,412 BTU/hr = 1 kW is the exact conversion relationship. This is the fundamental bridge between thermal and electrical power units. HVAC engineers use this daily to convert between heating/cooling capacity (BTU/hr) and electrical input power (kW).
What is a ton of refrigeration in SI units?
1 ton of refrigeration = 12,000 BTU/hr = 3.517 kW. This historically represents the cooling effect of melting one ton (2,000 lb) of ice in 24 hours. Modern chillers are rated from fractional tons to thousands of tons.
How does EER relate to this conversion?
EER (Energy Efficiency Ratio) = BTU/hr cooling ÷ Watts input. For example, a 12,000 BTU/hr AC unit drawing 1,200 W has an EER of 10. The conversion helps verify manufacturer efficiency claims across different unit systems.
Reviewed for accuracy
· Last reviewed: June 8, 2026
All calculations are for reference only. Always verify with manufacturer data and a qualified engineer for critical applications. Learn about our editorial process.