BTU / kW / Ton Converter

It converts a cooling (or heating) capacity between the units the industry mixes freely: BTU per hour, tons of refrigeration and kilowatts — with watts and kcal/h shown too. Enter a figure in whichever unit you have and read off the others, or use the common-sizes table for the standard air conditioner capacities.

One kilowatt is 3,412 BTU/hr. Going the other way, 1,000 BTU/hr is about 0.293 kW. So a "12,000 BTU" unit is 1 ton — roughly 3.5 kW of cooling — and an "18,000 BTU" unit is 1.5 tons, about 5.3 kW.

A ton is 12,000 BTU/hr — about 3.52 kW. The name is historical: it is the cooling delivered by melting one US ton of ice over 24 hours, from the days when ice was the refrigeration industry. It survives mainly in American equipment sizing, where a "3-ton" unit means 36,000 BTU/hr.

Split units typically come as 9,000 BTU (2.6 kW, 3/4 ton), 12,000 BTU (3.5 kW, 1 ton), 18,000 BTU (5.3 kW, 1.5 ton), 24,000 BTU (7 kW, 2 ton), 36,000 BTU (10.6 kW, 3 ton) and 60,000 BTU (17.6 kW, 5 ton). Nameplate names are rounded — the exact capacity is on the datasheet.

No — these units all describe the heat the system moves, not the electricity it draws. A 3.5 kW-cooling unit typically consumes around 1 kW of electricity, because a heat pump moves several times more heat than the energy it uses. Divide the capacity by the unit’s EER or COP to estimate the electrical draw.

In some markets aircons are sold by nominal horsepower, where 1 HP loosely corresponds to about 9,000 BTU/hr (2.6 kW) of cooling — a marketing convention, not the mechanical 746 W horsepower. Treat HP labels as size classes and check the datasheet BTU or kW figure for the real capacity.