How many kW is one ton of cooling?

One refrigeration ton is 3.517 kilowatts of heat removal, equivalent to 12,000 BTU/h — originally the heat needed to melt one short ton of ice per day. To convert a cooling load, divide kilowatts by 3.517 to get tons, or multiply tons by 3.517 to get kilowatts.

Is a cooling ton the same as electrical power?

No. Tons measure heat removed, not electricity consumed. A 20-ton air conditioner moves about 70 kW of heat while drawing roughly 23 kW of electricity at a coefficient of performance (COP) of 3. Always size rooms by cooling tons or kW-th, never by the unit’s electrical draw.

Formula · 1 min read

kW ↔ refrigeration tons

One refrigeration ton equals 3.517 kW of heat removal — converting is just division: tons = kW ÷ 3.517. A 70 kW cooling load is ≈ 19.9 tons.

Formula

tons = kW ÷ 3.517 · kW = tons × 3.517 · 1 ton = 12,000 BTU/h

A "ton of refrigeration" is pre-electricity HVAC vocabulary: the heat needed to melt one short ton (907 kg) of ice in 24 hours — 12,000 BTU/h, or 3.517 kW. Precision-cooling and building-HVAC vendors still quote in tons, so data-center kilowatts must cross this bridge.

Worked example

70 kW ÷ 3.517 = 19.9 tons · 12 tons × 3.517 = 42.2 kW

Try it

Cooling load (kW)Cooling capacity (tons)

70.0 kW = 19.9 tons · electrical draw ≈ 23.3 kW at COP 3

Common mistakes

Tons of cooling ≠ tons of electricity. A 20-ton unit removes 70 kW of heat but draws only ~23 kW from the grid at a typical COP of 3. Sizing rooms with electrical numbers understates cooling by two-thirds.
Nominal vs actual capacity. Nameplate tons are rated at standard conditions; at 35 °C ambient an AC delivers less. Derate or check the capacity table, same as liquid cabinets (approach temperature).

Room AC load (1.1× rule) · Room load calculation · Glossary

Sources

Definition: 1 ton of refrigeration = 12,000 BTU/h = 3.51685 kW (ASHRAE convention).