BTU per Hour to Watts Converter (BTU/h to W)
1 BTU/h = 0.293071 W. Convert air-conditioner, mini-split and furnace ratings in BTU (per hour) to watts of heating or cooling, with charts.
Watt (W) = British Thermal Unit per Hour (BTU/h) × 0.293071070172
British Thermal Unit per Hour (BTU/h): One International Table BTU per hour (BTU/h) is about 0.293071 W. In this power converter the shorthand BTU means BTU/h, as in cooling-capacity ratings; a quantity of BTU energy alone cannot be converted to watts without a time interval.
Watt (W): The watt (W) is the SI unit of power, one joule of energy per second. Light bulbs, appliances, chargers and electronics are rated in watts.
| British Thermal Unit per Hour (BTU/h) | Watt (W) |
|---|---|
| 1 | 0.293071070172 |
| 5 | 1.46535535086 |
| 10 | 2.93071070172 |
| 25 | 7.32677675431 |
| 50 | 14.6535535086 |
| 100 | 29.3071070172 |
Air conditioners, heat pumps and furnaces sold in North America are rated in "BTU", which on a spec sheet nearly always means BTU per hour, a rate of heat moved or produced. Watts measure the same kind of quantity, so the conversion is fixed: 1 BTU/h is about 0.293 W, and an air conditioner's 12,000 BTU/h is about 3.5 kW of cooling. Heat pumps use the same rating for heating, so a 24,000 BTU/h heat pump delivers about 7 kW of heat at its rated conditions.
Those watts are the heating or cooling output, not the electricity the unit uses. Divide the BTU/h rating by the efficiency rating (EER) to estimate the power draw: a 12,000 BTU/h unit with an EER of 12 draws about 1,000 watts from the outlet while moving about 3,500 watts of heat.
How to use this tool
- Type a value in the British Thermal Unit per Hour box to see it in watts, or type in the Watt box to convert the other way.
- Press ⇄ to swap the two units, or Load example for a typical value.
- Check the charts below for common values; for other units, open the Power converter.
Formula
Watt (W) = British Thermal Unit per Hour (BTU/h) × 0.293071070172
British Thermal Unit per Hour (BTU/h) = Watt (W) × 3.41214163313
Both factors come from exact definitions: 1 watt = 3.41214163313 British thermal units per hour and 1 british thermal unit per hour = 0.293071070172 watts (shown to 12 significant digits).
Example
Two conversions worked with the same factors the converter uses:
12000 BTU/h × 0.293071070172 ≈ 3516.85 W
3500 W × 3.41214163313 ≈ 11942.5 BTU/h
British Thermal Unit per Hour to Watt chart
Common values from British thermal units per hour to watts, rounded to four decimal places.
| British Thermal Unit per Hour (BTU/h) | Watt (W) |
|---|---|
| 1,000 | 293.0711 |
| 2,000 | 586.1421 |
| 3,000 | 879.2132 |
| 5,000 | 1,465.36 |
| 6,000 | 1,758.43 |
| 7,000 | 2,051.5 |
| 8,000 | 2,344.57 |
| 9,000 | 2,637.64 |
| 10,000 | 2,930.71 |
| 12,000 | 3,516.85 |
| 14,000 | 4,102.99 |
| 15,000 | 4,396.07 |
| 18,000 | 5,275.28 |
| 24,000 | 7,033.71 |
| 30,000 | 8,792.13 |
| 36,000 | 10,550.56 |
| 40,000 | 11,722.84 |
| 48,000 | 14,067.41 |
| 60,000 | 17,584.26 |
| 80,000 | 23,445.69 |
| 100,000 | 29,307.11 |
Watt to British Thermal Unit per Hour chart
The reverse direction for values people often look up.
| Watt (W) | British Thermal Unit per Hour (BTU/h) |
|---|---|
| 500 | 1,706.07 |
| 750 | 2,559.11 |
| 1,000 | 3,412.14 |
| 2,000 | 6,824.28 |
| 2,500 | 8,530.35 |
| 3,000 | 10,236.42 |
| 3,500 | 11,942.5 |
| 5,000 | 17,060.71 |
| 7,000 | 23,884.99 |
| 10,000 | 34,121.42 |
Heating and cooling capacities in BTU/h
| Equipment | British Thermal Unit per Hour (BTU/h) | Watt (W) |
|---|---|---|
| Smallest common window air conditioner | 5,000 | 1,465.36 |
| Ductless mini-split, a common small size | 9,000 | 2,637.64 |
| One ton of cooling capacity | 12,000 | 3,516.85 |
| Two-ton central air conditioner | 24,000 | 7,033.71 |
| Three-ton central air conditioner | 36,000 | 10,550.56 |
| Gas furnace, a common input rating | 80,000 | 23,445.69 |
Quick mental estimate
Multiply by 0.3, then take away 2%: 12,000 BTU/h → 3,600 − 72 = 3,528 W. The result is about 0.3% above the exact 3,517 W, close enough for sizing.
Use the converter or the charts when the exact figure matters.
The two units
British Thermal Unit per Hour (BTU/h): One International Table BTU per hour (BTU/h) is about 0.293071 W. In this power converter the shorthand BTU means BTU/h, as in cooling-capacity ratings; a quantity of BTU energy alone cannot be converted to watts without a time interval.
Watt (W): The watt (W) is the SI unit of power, one joule of energy per second. Light bulbs, appliances, chargers and electronics are rated in watts.
Frequently asked questions
How many watts is a 12,000 BTU air conditioner?
Its cooling output is about 3,517 W, one refrigeration ton. The electricity it uses is much lower, often roughly 1,000 to 1,200 W depending on its efficiency rating.
Does BTU on an air conditioner mean BTU per hour?
Yes. Capacity ratings are a rate, so "12,000 BTU" on a label is shorthand for 12,000 BTU per hour. An amount of energy in BTU, without the per hour, converts on the BTU to kWh converter instead.
What is a ton of cooling in watts?
A refrigeration ton is 12,000 BTU per hour, about 3.517 kW. The name comes from the heat needed to melt a short ton of ice in 24 hours.
How precise is the result?
The converter uses the exact definitions above with browser floating-point arithmetic and shows up to 12 significant digits. The charts round to four decimal places for reading.
Sources
Last updated:
Page address with these inputs: https://kakao.mobile/tools/btu-to-watt-converter/
Cite or embed this tool
kakaoCalc. (2026, November 8). BTU per Hour to Watts Converter (BTU/h to W). https://kakao.mobile/tools/btu-to-watt-converter/
“BTU per Hour to Watts Converter (BTU/h to W).” kakaoCalc, 8 Nov. 2026, kakao.mobile/tools/btu-to-watt-converter/.
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