kW to BTU converter
One kilowatt is 3,412 BTU/h.
Your inputs
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Example loaded. You can change any value.
There is no figure yet: nothing is calculated until you ask for it.
- Enter your measurements.
- Check the units and the assumptions.
- Press Calculate, or load the example.
Rather see a worked case? Press “Load example” and change any value afterwards.
Next step
The BTU is still capacity; the EER says how much electricity it takes to deliver it.
Where each number comes from Conversion constants are exact; densities and coverage rates come from cited sources; everything else is an assumption you can change. Methodology · Sources and updates
How to use it
- Enter the capacity in kW from the quote or the data sheet.
- Check first that these are capacity kW and not power input.
- Read the BTU/h: that is what you will search shops and comparison sites with.
- Look at the commercial step: 3.5 kW lands on the catalogue's 12,000 BTU.
How it is calculated
Installers quote in kW and shops advertise in BTU. This conversion is for checking that the unit in the quote and the one you saw on offer are the same machine, before arguing about the price.
It runs the opposite way to BTU to kW, and that moves where the risk sits: the starting figure comes off a data sheet with several kW numbers on it, so the first job is making sure which one you are copying.
The conversion, exactly
All three units measure the same thing, energy per unit of time, and only the scale changes: the watt belongs to the SI, the BTU/h to English-speaking markets and the frigorie per hour to Spain and Latin America. The ton of refrigeration, used on larger equipment, is 12,000 BTU/h by definition.
Worked example
A 3.5 kW unit:
- 3.5 x 3,412.14 = 11,942 BTU/h
- In frigories: 3,009 frigories/h
- Commercial size: 12,000 BTU/h
European 3.5 kW units are the ones sold as 12,000 BTU elsewhere: the difference is 0.5 %.
Good to know
- Check which row you took the kW from. A data sheet carries cooling capacity, heating capacity and power input, all three in kW. This converter wants the first.
- 3.5 kW is 11,942 BTU/h. They are sold as 12,000 units: half a percentage point of difference, which in practice tells no two machines apart.
- Heating capacity is usually higher than cooling capacity. If the unit is a heat pump, do not mix the two figures when comparing models.
Frequently asked questions
How many BTU is 3.5 kW?
11,942 BTU/h, essentially a 12,000 BTU commercial unit.
How many BTU is 1 kW?
3,412.14 BTU/h. An exact constant derived from the definition of the international BTU.
How many kW is a 2,500-frigorie unit?
2,500 frigories is 2,908 W, so 2.9 kW of cooling capacity.
Can I use this to work out consumption?
No. This converts cooling capacity. For consumption you need the efficiency rating or the rated electrical input.