How to convert watts to BTU per hour
Formula: BTU/h = W × 3.41214
Worked example: 1,500 W → 1,500 × 3.41214 = 5,118.21 BTU/h
One watt equals about 3.412 BTU per hour. A 1,500 W space heater puts out about 5,118 BTU/h, the same as any other 1,500 W electric heater, whatever its design.
Watts to BTU per hour conversion chart
| Watts (W) | BTU per hour (BTU/h) |
|---|---|
| 1 W | 3.41214 BTU/h |
| 2 W | 6.82428 BTU/h |
| 3 W | 10.2364 BTU/h |
| 4 W | 13.6486 BTU/h |
| 5 W | 17.0607 BTU/h |
| 6 W | 20.4728 BTU/h |
| 7 W | 23.885 BTU/h |
| 8 W | 27.2971 BTU/h |
| 9 W | 30.7093 BTU/h |
| 10 W | 34.1214 BTU/h |
| 12 W | 40.9457 BTU/h |
| 15 W | 51.1821 BTU/h |
| 20 W | 68.2428 BTU/h |
| 25 W | 85.3035 BTU/h |
| 30 W | 102.364 BTU/h |
| 40 W | 136.486 BTU/h |
| 50 W | 170.607 BTU/h |
| 75 W | 255.911 BTU/h |
| 100 W | 341.214 BTU/h |
| 250 W | 853.035 BTU/h |
| 500 W | 1,706.07 BTU/h |
| 1,000 W | 3,412.14 BTU/h |
What is a watt?
The watt is the SI unit of power: one joule of energy per second. Light bulbs, chargers and small appliances are rated in watts; an LED bulb draws about 9 W and a hair dryer up to 1,800 W.
What is one BTU per hour?
BTU per hour is the US unit for heating and cooling capacity, about 0.293 watt. Window air conditioners range from 5,000 to 15,000 BTU/h, and the label often drops the per hour and simply says BTU.