Watts to BTU and BTU to Watts Conversions

rv air conditoner w300pxWatts to BTU and BTU to Watts conversions are commonly required when calculating the power of devices that are used for air heating and cooling, like various AC units and electric heaters.

'Slight' issue is the fact that BTU is a unit of energy, while watts are a unit of power, and they can't directly be converted.

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What is a BTU?

BTU is a unit of heat and it stands for the British Thermal Unit. BTU is defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit.

Note: BTU is also part of the United States customary units.

BTU's counterpart in the metric system of units is the calorie - the amount of heat required to raise the temperature of one gram of water by one degree Celsius.

Although there are several definitions of both BTU and calorie, 'standard' units are:

1 calorie = 4.184 J (Joules)

1 BTU = 1055.06 J (Joules)

Since watts are a measure of power, and the BTU is a unit of energy, watts are actually compared with the BTU per hour (BTU/hr).

When converting watts to BTU/hr and BTU/hr to watts, these formulas are used:

1 BTU/hr = 0.29307107 watts = ~0.2931 watts

1 W = 3.412141635 BTU/hr = ~3.412142 BTU/hr 


Watts to BTU and BTU to Watts Conversion Charts

If You have the need to quickly convert Watts to BTU/hr and BTU/hr to Watts, feel free to use these conversion charts:

Power (watts) Power (BTU/hr)
1 3.412142
5 17.060708
10 34.12142
50 170.60708
100 341.2142
500 1706.0708
1000 3412.142
1500 5118.212
2000 6824.283
5000 17060.708
 
Power (BTU/hr) Power (watts)
1 0.29307107
10 2.9307107
100 29.307107
500 146.53553
1000 293.07107
2000 586.14214
5000 1465.3553
8000 2344.5685
10000 2930.7107
15000 4396.0660


 Watts to BTU and BTU to Watts Conversion Calculators

In order to convert Watts to BTU/hr and BTU/hr, feel free to use these conversion calculators - write the value that You have and click 'Calculate' to convert it:

Power (Watts) to Power (BTU/hr)

 

Power (BTU/hr) to Power (Watts)

Power (Watts):

Power (BTU/hr):

 

Power (BTU/hr):

Power (Watts):


Long Story Short: When converting two units, they must be the same units or one unit must be converted into another unit, using an additional parameter - in this case, BTU/hr are converted directly into watts, and not BTU.

When calculating required electric power for AC units, note that these units feature 'heat pumps' and their BTU/hr values (ability to warm up or cool down certain areas) are not equal to their requirements in watts.

For example, a typical 15.000 BTU (actually, this is BTU/hr, but it is customary to write just BTU - more opportunities for confusion) window air conditioner on average requires 1900 Running Watts and 2900 Starting Watts. But, as the technology improves, these ratings in watts are decreasing over time.

For more about this topic feel free to check our Will a 2000-Watt Generator Run an Air Conditioner? article.