BTU Conversion Chart: BTU/h to Watts, kW, Tons and kWh
Part of the project planner: Planning heating, cooling and ventilation.
A BTU per hour is a rate of heating or cooling: 1 BTU/h = 0.2931 watts, so 12,000 BTU/h = 3,517 watts = 1 ton of cooling. A 1,500 watt space heater makes 5,118 BTU/h. For energy, 1 kWh = 3,412 BTU and 1 therm is 29.3 kWh. The BTU converter does any amount.
BTU per hour in other units
| BTU/h | Watts | Kilowatts | Tons | Horsepower |
|---|---|---|---|---|
| 5,000 | 1,465 | 1.47 | 0.42 | 1.97 |
| 6,000 | 1,758 | 1.76 | 0.50 | 2.36 |
| 8,000 | 2,345 | 2.34 | 0.67 | 3.14 |
| 10,000 | 2,931 | 2.93 | 0.83 | 3.93 |
| 12,000 | 3,517 | 3.52 | 1.00 | 4.72 |
| 15,000 | 4,396 | 4.40 | 1.25 | 5.90 |
| 18,000 | 5,275 | 5.28 | 1.50 | 7.07 |
| 24,000 | 7,034 | 7.03 | 2.00 | 9.43 |
| 30,000 | 8,792 | 8.79 | 2.50 | 11.79 |
| 36,000 | 10,551 | 10.55 | 3.00 | 14.15 |
| 48,000 | 14,067 | 14.07 | 4.00 | 18.86 |
| 60,000 | 17,584 | 17.58 | 5.00 | 23.58 |
| 80,000 | 23,446 | 23.45 | 6.67 | 31.44 |
| 100,000 | 29,307 | 29.31 | 8.33 | 39.30 |
Heaters in watts and BTU
| Heater | BTU per hour |
|---|---|
| 500 W | 1,706 |
| 750 W | 2,559 |
| 1,000 W | 3,412 |
| 1,500 W | 5,118 |
| 2,000 W | 6,824 |
| 3,000 W | 10,236 |
| 5,000 W | 17,061 |
Every watt of an electric heater becomes 3.412 BTU per hour of heat. To choose a size for a room, see the space heater size calculator, the furnace size calculator or the air conditioner size calculator.
Energy: BTU, kWh, therms and MJ
| Amount | BTU | kWh | Therms | Megajoules |
|---|---|---|---|---|
| 1 kWh | 3,412 | 1.000 | 0.0341 | 3.60 |
| 1 therm | 100,000 | 29.307 | 1.0000 | 105.51 |
| 1 MMBtu | 1,000,000 | 293.071 | 10.0000 | 1,055.06 |
| 100,000 BTU | 100,000 | 29.307 | 1.0000 | 105.51 |
| 1 MJ | 948 | 0.278 | 0.0095 | 1.00 |
| 1,000 kcal | 3,968 | 1.163 | 0.0397 | 4.19 |
Where each unit is used
- BTU/h and tons: air conditioners, furnaces, boilers and heat pumps are rated in BTU per hour, and cooling capacity in tons (12,000 BTU/h).
- Watts and kW: electric heaters, appliances and motors.
- kWh: electricity bills.
- Therms and ccf: natural gas bills. A therm is 100,000 BTU; a ccf (hundred cubic feet) is about 1.03 therms.
- MJ and kcal: energy in other countries and for fuel and food labels.
Heat versus electricity
The BTU rating of an air conditioner or heat pump is the heat it moves, not the power it draws. A heat pump may move three to four units of heat for each unit of electricity it uses, which is why it can be much cheaper to run than a resistance heater: compare fuels in the heating cost comparison.
Frequently asked questions
How many watts is 12,000 BTU?
12,000 BTU per hour is 3,517 watts (3.52 kW), which is one ton of cooling.
How many BTU is 1,500 watts?
5,118 BTU per hour, the output of a standard space heater.
How many BTU in a ton of air conditioning?
12,000 BTU per hour. A 3-ton air conditioner is 36,000 BTU/h.
How many BTU in a kilowatt-hour?
3,412 BTU. A therm (100,000 BTU) is 29.3 kWh.
Does a 12,000 BTU air conditioner use 12,000 BTU of electricity?
No. The rating is the heat it removes. It uses roughly a third of that as electricity: about 1,000 to 1,500 watts for a 12,000 BTU unit.
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Estimates only. Quantities depend on your materials, site and supplier. Confirm important numbers before you order, and follow local building codes for anything structural.