Watts to BTU Calculator
Convert electrical heating or cooling power from watts (W) to BTU/hr.
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BTU/hr
Formula: BTU/hr = W × 3.412142
How to convert Watts to BTU/hr
The formula is BTU/hr = Watts × 3.412142.
For example, a 1500 W space heater will output approximately 5118 BTU/hr. Resistive electric heating is 100% efficient, so the electrical watts equal the thermal watts output.
Common Watts to BTU/hr Conversions
| Watts (W) | BTU/hr |
|---|---|
| 100 W | 341 BTU/hr |
| 500 W | 1,706 BTU/hr |
| 1,000 W | 3,412 BTU/hr |
| 1,500 W | 5,118 BTU/hr |
| 2,000 W | 6,824 BTU/hr |
Frequently Asked Questions
Why convert watts to BTU?
BTU is the standard measurement for HVAC systems in the United States, so converting electrical power to BTU helps you size a space heater or understand the cooling equivalent of your equipment.
Are all watts converted to heat?
For a purely resistive electric heater, yes, essentially 100% of the electrical watts are converted to heat (thermal watts), which equals 3.412 BTU/hr per watt.
Is a BTU the same as a ton of AC?
No, but they measure the same thing. One "ton" of refrigeration capacity is equal to 12,000 BTU/hr.