Btu to kW Converter
A heater label may say Btu/h, while a power bill speaks in kW. Divide Btu/h by 3,412.14 to switch.
Quick answer: multiply the result in Btu/h by 0.00029307. For example, 10,000 Btu/h is 2.931 kW, 12,000 Btu/h is 3.517 kW and 36,000 Btu/h is 10.551 kW.
The Btu/h to kW formula
One watt is about 3.412142 Btu per hour (Wikipedia: British thermal unit).
So 1 kW is 3,412.142 Btu/h, and you divide the Btu/h by that.
Take 10,000 Btu/h. Multiply by 0.00029307. The answer is 2.931 kW.
Take 12,000 Btu/h. Multiply by 0.00029307. The answer is 3.517 kW.
Btu per hour to kilowatts
Btu/h means British thermal units per hour, a rate of heat flow.
kW means kilowatts, which is 1,000 watts.
The factor 0.00029307 joins the two.
How to convert Btu/h to kW step by step
- Write down the result in Btu/h.
- Multiply it by 0.00029307.
- The answer is in kW.
- Check it against the chart above.
Example 1: 10,000 Btu/h
- Start with 10,000 Btu/h.
- 10,000 × 0.00029307 = 2.931.
- The result is 2.931 kW.
10,000 Btu/h = 2.931 kW
Example 2: 12,000 Btu/h
- Start with 12,000 Btu/h.
- 12,000 × 0.00029307 = 3.517.
- The result is 3.517 kW.
12,000 Btu/h = 3.517 kW
Example 3: 36,000 Btu/h
- Start with 36,000 Btu/h.
- 36,000 × 0.00029307 = 10.551.
- The result is 10.551 kW.
36,000 Btu/h = 10.551 kW
This is thermal power, not the electrical power the machine draws.
Btu/h to kW conversion table
| Btu/h | kW | W |
|---|---|---|
| 10,000 Btu/h | 2.931 kW | 2,930.71 W |
| 12,000 Btu/h | 3.517 kW | 3,516.85 W |
| 36,000 Btu/h | 10.551 kW | 10,550.56 W |
| 60,000 Btu/h | 17.584 kW | 17,584.26 W |
| 5,000 Btu/h | 1.465 kW | 1,465.36 W |
| 100,000 Btu/h | 29.307 kW | 29,307.1 W |
| 1,000 Btu/h | 0.2931 kW | 293.07 W |
The highlighted row, 10,000 Btu/h, is the default of the converter. The last column gives W.
A quick mental shortcut for Btu/h to kW
Divide by 3,400 for a quick estimate.
So 10,000 Btu/h is about 2.9 kW.
What Btu/h measures
Btu/h means British thermal units per hour, a rate of heat flow.
It is used mainly in North America for heating and cooling (Wikipedia: British thermal unit).
What kW measures
kW means kilowatts, which is 1,000 watts.
The watt is the SI unit of power for heating and cooling (Wikipedia: British thermal unit).
Worked example: 60,000 Btu/h
60,000 Btu/h times the factor gives 17.584 kW.
Check it by dividing 17.584 by the factor, which returns 60,000.
Worked example: 36,000 Btu/h
36,000 Btu/h times the factor gives 10.551 kW.
Check it by dividing 10.551 by the factor, which returns 36,000.
Why watts and Btu/h both exist
Btu/h is common on North American heating and cooling labels.
The watt is the SI unit, so most other places use kW.
A link to tons of cooling
One ton of cooling is 12,000 Btu/h, which is about 3.52 kW (Wikipedia: Ton of refrigeration).
So a 3 ton air conditioner is about 10.6 kW of cooling.
A heater example
A heater rated at 60,000 Btu/h gives about 17.584 kW of heat.
That is the heat output, not the power it draws.
Going the other way
To go back, multiply the kW by 3,412.14.
So 2.93 kW is about 10,000 Btu/h.
Check your answer
Your answer should be smaller than your starting number.
Reverse the sum and you should get your first number back.
More worked values
24,000 Btu/h is 7.0337 kW, 6,000 Btu/h is 1.7584 kW and 100,000 Btu/h is 29.307 kW.
A furnace and a bill
A 60,000 Btu/h furnace gives about 17.6 kW of heat. Run for an hour, it gives about 17.6 kWh of heat.
An electric heater would need 17.6 kW of power to match it.
Checking your result
Multiply the kW by 3,412.14. 7.0337 kW times 3,412.14 gives back 24,000 Btu/h.
More values at a glance
3,000 Btu/h is 0.87921 kW, 9,000 Btu/h is 2.6376 kW and 18,000 Btu/h is 5.2753 kW.
48,000 Btu/h is 14.067 kW, and 72,000 Btu/h is 21.101 kW.
The unit sizes
One kW is about 3,412 Btu/h. Divide the Btu/h by 3,412 to get kW.
If a result looks very large or very small, compare it with these sizes before you use it.
Quick conversion answers
| Conversion | Result |
|---|---|
| 10,000 Btu/h | 2.931 kW |
| 12,000 Btu/h | 3.517 kW |
| 36,000 Btu/h | 10.551 kW |
| 60,000 Btu/h | 17.584 kW |
| 5,000 Btu/h | 1.465 kW |
| 100,000 Btu/h | 29.307 kW |
Round numbers for Btu/h and kW
Use these round numbers to check your own answer. 50,000 Btu/h is 14.65 kW, 500,000 Btu/h is 146.5 kW and 5,000,000 Btu/h is 1,465 kW.
Going the other way, 5 kW is 17,060 Btu/h, 50 kW is 170,600 Btu/h and 500 kW is 1,706,000 Btu/h.
A round trip with Btu/h
Say you start with 370,000 Btu/h. It becomes 108.4 kW. Divide that by the factor and you land on 370,000 Btu/h again.
Now start from 250 kW instead. It becomes 853,000 Btu/h, and multiplying by the factor returns 250 kW.
Where this conversion is used
Heating and cooling gear is rated in Btu.
Motors, chillers and heaters are rated in kW.
Common mistakes to avoid
- Mixing up the direction. Going from Btu/h to kW should make the number smaller.
- Mixing Btu and Btu/h. A Btu is energy, while Btu/h is power. This page needs Btu per hour.
- Mixing kW and kWh. A kW is power, and a kWh is energy.
- Rounding too early. The answer for 36,000 Btu/h is 10.551 kW. Cut it to 11 kW and you are off by about 4.3 percent, and the gap grows if you reuse it.
Related converters
Example: 5,000 Btu/h
5,000 Btu/h times the factor gives 1.4654 kW.
Check it by dividing 1.4654 by the factor, which returns 5,000.
Example: 100,000 Btu/h
100,000 Btu/h times the factor gives 29.307 kW.
Check it by dividing 29.307 by the factor, which returns 100,000.
Frequently asked questions
How do I convert Btu/h to kW?
divide by 3,412.14.
How many kW is 10,000 Btu/h?
2.9307 kW.
How many kW is 12,000 Btu/h?
3.5169 kW.
How many Btu/h is 1 kW?
About 3,412.1 Btu/h.
How many kW is 10 Btu/h?
0.0029307 kW.
How many kW is 100 Btu/h?
0.029307 kW.
Sources
- Wikipedia: British thermal unit (en.wikipedia.org)
- Wikipedia: Ton of refrigeration (en.wikipedia.org)
