How to convert BTU per hour to watts
One BTU per hour equals 0.293071 watts, so multiply the number of BTU per hour by 0.293071:
W = BTU/h × 0.293071
BTU/h = W ÷ 0.293071 (1 W = 3.4121 BTU/h)
Example: 5,000 BTU/h → 5,000 × 0.293071 = 1,465.36 W.
Going the other way, divide by 0.293071, or multiply by 3.4121; the watts to BTU per hour converter does it for you.
Everyday values
| BTU per hour | Watts | For example |
|---|---|---|
| 5,000 BTU/h | 1,465.36 W | a small window air conditioner |
| 9,000 BTU/h | 2,637.64 W | a 9,000 BTU split AC |
| 12,000 BTU/h | 3,516.85 W | a 12,000 BTU (one-ton) AC |
| 18,000 BTU/h | 5,275.28 W | an 18,000 BTU AC |
| 24,000 BTU/h | 7,033.71 W | a 24,000 BTU AC |
When you need this conversion
Air conditioners are sold by cooling capacity in BTU per hour (often written simply "BTU"). 12,000 BTU/h is 3.52 kW of cooling. This is cooling output, not the electricity the unit uses: with an efficiency (COP) of around 3, a 3.5 kW AC draws roughly 1.2 kW of electricity.
BTU per hour to watt conversion table
| BTU/h | W | BTU/h | W |
|---|---|---|---|
| 1,000 BTU/h | 293.071 W | 13,000 BTU/h | 3,809.92 W |
| 2,000 BTU/h | 586.142 W | 14,000 BTU/h | 4,102.99 W |
| 3,000 BTU/h | 879.213 W | 15,000 BTU/h | 4,396.07 W |
| 4,000 BTU/h | 1,172.28 W | 16,000 BTU/h | 4,689.14 W |
| 5,000 BTU/h | 1,465.36 W | 17,000 BTU/h | 4,982.21 W |
| 6,000 BTU/h | 1,758.43 W | 18,000 BTU/h | 5,275.28 W |
| 7,000 BTU/h | 2,051.5 W | 19,000 BTU/h | 5,568.35 W |
| 8,000 BTU/h | 2,344.57 W | 20,000 BTU/h | 5,861.42 W |
| 9,000 BTU/h | 2,637.64 W | 21,000 BTU/h | 6,154.49 W |
| 10,000 BTU/h | 2,930.71 W | 22,000 BTU/h | 6,447.56 W |
| 11,000 BTU/h | 3,223.78 W | 23,000 BTU/h | 6,740.63 W |
| 12,000 BTU/h | 3,516.85 W | 24,000 BTU/h | 7,033.71 W |
About the units
- BTU per hour (BTU/h): one International Table BTU per hour, about 0.2931 W.
- Watt (W): one joule per second, the SI unit of power.
Both are units of power. The conversion factor comes from the exact definitions above, so the calculator is exact; results are only rounded for display (up to six significant digits).
Frequently asked questions
How many watts are in one BTU per hour?
One BTU per hour is 0.293071 watts. One watt is 3.4121 BTU per hour.
How do I convert BTU per hour to watts?
Multiply the value in BTU per hour by 0.293071. To go back, divide by 0.293071.
What is 5,000 BTU/h in watts?
5,000 BTU/h = 1,465.36 W.
What is 9,000 BTU/h in watts?
9,000 BTU/h = 2,637.64 W.
Sources
- NIST Special Publication 811 (2008), Guide for the Use of the International System of Units (SI), Appendix B: conversion factors.
- NIST Handbook 44 (2024), Appendix C: General tables of units of measurement.
Last reviewed 5 October 2026. Results are estimates; see our disclaimer.