BTU to Watts: Convert BTU per Hour to Watts
Convert BTU/hr to watts: 1 BTU/hr = 0.293 W. Instant converter, a table of common AC and heater sizes, and why label watts differ from cooling watts.
Watts
Formula: W = BTU/hr ÷ 3.412
Going the other way? Watts to BTU converter.
BTU/hr to W conversion table
| BTU per hour | Watts |
|---|---|
| 1,000 BTU/hr | 293 W |
| 2,000 BTU/hr | 586 W |
| 3,412 BTU/hr | 1,000 W |
| 5,000 BTU/hr | 1,465 W |
| 6,000 BTU/hr | 1,758 W |
| 8,000 BTU/hr | 2,345 W |
| 10,000 BTU/hr | 2,931 W |
| 12,000 BTU/hr | 3,517 W |
| 15,000 BTU/hr | 4,396 W |
| 18,000 BTU/hr | 5,275 W |
| 24,000 BTU/hr | 7,034 W |
| 30,000 BTU/hr | 8,792 W |
| 36,000 BTU/hr | 10,551 W |
| 48,000 BTU/hr | 14,067 W |
About this conversion
One BTU per hour is 0.293 watts, so divide BTU/hr by 3.412 to get watts. The result is a rate of heat flow expressed in the metric unit, and it is exact: a 10,000 BTU/hr heat load is a 2,931 W heat load, no matter what equipment handles it.
The trap is that the watt figure on an air conditioner's label is something else entirely. That is the electrical input the unit draws, not the heat it removes. A 12,000 BTU window AC removes 3,517 W of heat but might draw only 1,000 to 1,200 W from the wall, because a refrigeration cycle moves roughly three units of heat for every unit of electricity it consumes. The ratio between the two is the unit's EER (in BTU/hr per watt) or, in metric terms, its coefficient of performance.
For electric resistance heaters the two numbers coincide: a 1,500 W space heater draws 1,500 W and delivers 1,500 W of heat (5,118 BTU/hr), because resistance heating is essentially 100% efficient at converting electricity to heat. That is why the watts-to-BTU conversion is the one you actually want when sizing a space heater or baseboard.
Need the load for a specific room rather than a unit conversion? Use the BTU calculator, which returns BTU/hr, tons, kW and watts together.
Quick answers
How many watts is 12,000 BTU?
About 3,517 W of heat removal. The air conditioner itself draws roughly 1,000–1,200 W of electricity to do it.
How many watts is 5,000 BTU?
About 1,465 W of cooling capacity. A 5,000 BTU window unit typically draws 400–500 W.
Is BTU to watts the same for heaters and air conditioners?
The heat conversion is identical (÷ 3.412). But for an electric heater the watts of heat equal the watts of electricity, while an AC or heat pump delivers 2.5–4 times more heat than the electricity it uses.