BTU to frigories converter
For comparing units advertised in different markets.
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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 third unit on the same label: the kW of the European catalogue.
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 BTU/h from the listing or the manufacturer's data sheet.
- Read the frigories per hour: that is the number a Spanish installer will use.
- Check whether it lands near a commercial step (2,250, 3,000 or 4,500 frigories).
- The kW on the same row are what the European energy label shows.
How it is calculated
This is the conversion for buying abroad and installing at home. Units advertised in big retailers and online shops often come in BTU, while the installer, the neighbour and the quote all speak in frigories.
Translating the figure before asking for a quote heads off the most expensive misunderstanding in this purchase: thinking that "12,000" and "3,000" describe different machines when they are the same one.
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 12,000 BTU/h unit:
- In watts: 12,000 x 0.29307107 = 3,517 W
- In frigories: 3,517 / 1.163 = 3,024 frigories/h
- In kW: 3.52 kW
A 12,000 BTU unit has slightly more than 3,000 frigories, not exactly 3,000.
Good to know
- 12,000 BTU is 3,024 frigories, not 3,000. The gap is small, but it explains why catalogues from the two markets never quite line up.
- "BTU" almost always means BTU/h. A plain BTU is energy; what an air conditioner has is power, so BTU per hour. Listings drop the "per hour".
- The British and international BTU are not identical. The differences sit in the fifth decimal, and the figure used here is the international (IT) BTU, which is the one the industry uses.
Frequently asked questions
How many frigories is 12,000 BTU?
3,024 frigories/h. The exact conversion is multiplying BTU/h by 0.2519958.
How many frigories is 9,000 BTU?
2,268 frigories/h, which the market usually calls a 2,250-frigorie unit.
And 18,000 BTU?
4,536 frigories/h, about 5.3 kW of cooling capacity.
Why do the commercial numbers not line up?
Because each market rounds to a round number in its own unit: 12,000 BTU in some places, 3,000 frigories in others, and both describe roughly the same machine.