Watts to BTU and BTU to Watts Conversions
Watts 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.
Updated: January 25, 2022.
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What is a BTU?
BTU is a unit of heat (energy) 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
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:
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)
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 (and not BTU) are converted directly into watts.
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.
Watts to BTU and BTU to Watts Frequently Asked Questions (FAQ)
Here are some of the most common Watts to BTU and BTU to Watts Frequently Asked Questions (FAQ):
Again, it is important to remember that the BTU is a unit of energy and BTU/h and Watts are units of power.
How many BTU is 1000 watts?
If You check the conversion chart or use our conversion calculator, You can find out that 1000 watts are 3412 BTU/h - again, these are BTU per hour (power) and not BTU (energy).
But, in everyday conversation, one often uses BTU (energy) instead of BTU/h (power) and may say that 1000W is equal to 3412 BTU, which is actually not correct, but ...
How many BTU is 1700 watts?
1700 watts equals ~5800 BTU/h.
How many BTU is 1800 watts?
1800 watts equals ~6141 BTU/h.
How many BTU is 2000 watts?
2000 watts equals ~6824 BTU/h.
How many BTU is 3500 watts?
3500 watts equals ~11942 BTU/h.
How many BTU is 5000 watts?
5000 watts equals ~17060 BTU/h.
How many watts is 15000 BTU?
15000 BTU/h equals ~4396 Watts.
How many watts is 40000 BTU?
40000 BTU/h equals ~11722 Watts.
How many watts does it take to run a 10000 BTU AC?
Depending on its energy class, 10000 BTU AC requires on average 900-1200 running watts and 1500-2000 starting watts.
Also, 10000 BTU AC heats (or cools) area with heating (or cooling) power of ~2930 watts.
How many watts does it take to run a 13500 BTU AC?
Similar to the previous question, depending on its energy class, 13500 BTU AC requires on average 1400-1700 running watts and 2400-2700 starting watts - more energy-efficient units require less power for the same heating (or cooling) effect.
Also, 13500 BTU AC heats (or cools) area with heating (or cooling) power of ~3956 watts.
Will a 2000-watt inverter generator run a 5000 BTU AC?
5000 BTU AC units require on average 500-700 running watts and 800-1100 starting watts. Since 2000 watts inverter power generators feature running watts of ~2000 Watts and the starting watts of 2000-2500+ watts, it is safe to say that 2000 watts inverter power generators are able to run 5000 BTU AC.
Again, for more about this topic feel free to check our Will a 2000-Watt Generator Run an Air Conditioner? article.