kW to BTU converter
One kilowatt is 3,412 BTU/h.
Your inputs
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- 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
- Type the amount you want to convert.
- The result appears immediately, with every equivalent.
- Check the nearest commercial size too.
- If the unit is advertised in another unit, use the reverse conversion.
How it is calculated
This is an exact conversion between units of power. They all measure the same thing (energy per unit of time), only the scale changes:
The three units that meet in air conditioning are the watt (SI), the BTU/h (English-speaking markets) and the frigorie per hour (Spain and Latin America). The ton of refrigeration, used for larger equipment, is 12,000 BTU/h by definition.
Keep in mind that all of these describe cooling capacity, that is, heat removed. Electricity consumption is a different quantity.
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
- Capacity is not consumption. The BTU/h, frigories or kW on a label measure the heat the unit removes from the room, not the electricity it uses. For that you need the efficiency rating or the rated input power.
- Commercial sizes come in steps. Domestic units are built at 9,000, 12,000, 18,000 and 24,000 BTU/h, so the exact figure rarely matches a real model.
- Watch the round marketing numbers. A unit advertised as "3,000 frigories" is actually 11,905 BTU/h, and is usually sold as a 12,000.
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.