Convert cooling capacity in kilowatts to tons of refrigeration for chiller and plant selection.
For the electrical side of the same plant, use the main kVA to kW converter.
Every diagram and table on this page updates with the calculator above.
One ton of refrigeration is 12,000 BTU/hr, or 3.51685 kW.
The unit dates from the ice trade. Before mechanical refrigeration, cooling was sold by the ton of ice delivered; when machines replaced ice, the rating stuck.
A ton of refrigeration is the cooling produced by melting one short ton of ice over 24 hours. Nothing about the equipment weighs a ton.
| Machine type | Typical range | In kW |
|---|---|---|
| Split air conditioner | 1 – 5 TR | 3.5 – 18 kW |
| Packaged rooftop unit | 5 – 25 TR | 18 – 88 kW |
| Air-cooled scroll chiller | 20 – 150 TR | 70 – 530 kW |
| Air-cooled screw chiller | 100 – 500 TR | 350 – 1,760 kW |
| Water-cooled centrifugal | 200 – 3,000 TR | 700 – 10,500 kW |
Standard cooling capacities in kilowatts, tons and BTU per hour.
| kW | Refrigeration (tons) | Heat rate (BTU/hr) |
|---|---|---|
| 3.5 kW | 1 | 11,942 |
| 7 kW | 1.99 | 23,885 |
| 10.5 kW | 2.99 | 35,827 |
| 17.6 kW | 5 | 60,054 |
| 35 kW | 9.95 | 119,425 |
| 53 kW | 15.07 | 180,844 |
| 70 kW | 19.9 | 238,850 |
| 105 kW | 29.86 | 358,275 |
| 176 kW | 50.04 | 600,537 |
| 352 kW | 100.09 | 1,201,074 |
| 528 kW | 150.13 | 1,801,611 |
| 703 kW | 199.89 | 2,398,736 |
| 1,055 kW | 299.98 | 3,599,810 |
| 1,400 kW | 398.08 | 4,776,999 |
This is the single most expensive mistake in plant room sizing. Cooling tons describe heat removed; the electricity consumed is several times smaller, because a chiller moves heat rather than creating it.
COP is coefficient of performance — cooling delivered per unit of electricity consumed.
The supply needs about 70 kW, not 352 kW. Sizing the feeder on the cooling figure would cost five times more than necessary.
From a proper heat load calculation at the design condition, including diversity between gains.
Two units at 60% each cost more but keep the building running during maintenance or a failure.
Most plant runs at 40–60% for most of the year. IPLV matters far more than peak efficiency.
Air-cooled is simpler; water-cooled is more efficient but adds a cooling tower and water treatment.
Input kW, starting current and any soft-start or VSD requirement.
The relationship is a straight line, so interpolation between standard sizes is always safe. What is not linear is cost or efficiency — both improve with scale up to a point, then plateau.
29 calculators built on the same maths as the tool above. Each one has its own inputs, interactive diagrams and worked examples.
Common questions about converting kw to ton.