Convert TR (Refrigeration Tons) to kW
| ton of refrigeration | kW |
|---|---|
| 0.5 | 1.758 |
| 1 | 3.517 |
| 1.5 | 5.275 |
| 2 | 7.034 |
| 3 | 10.55 |
| 5 | 17.58 |
| 10 | 35.17 |
| 20 | 70.34 |
| 50 | 175.8 |
| 100 | 351.7 |
Each row uses the same factor as the converter above: 1 ton of refrigeration = 3.517 kW.
One ton of refrigeration (1 TR, the “ton” in an air conditioner or chiller rating) is 3.516853 kW — exactly 12,000 BTU per hour. The unit is a genuine historical artefact: it is the rate of cooling you get from melting one short ton of ice over twenty-four hours, which is how cooling was actually sold before mechanical refrigeration existed. That is why the number behind it is 12,000 rather than something round.
To convert tons of refrigeration to kilowatts, multiply by 3.5169. So a 100-ton chiller is 351.7 kW of cooling capacity. To go the other way, multiply kilowatts by 0.28435 — 100 kW of cooling is 28.4 tons.
kW = tons × 3.516853. Reverse: tons = kW × 0.284345. The figure is exact by definition: 12,000 British thermal units per hour, where the International Table BTU is exactly 1,055.05585262 joules, spread over 3,600 seconds. Nothing here was measured.
| Refrigeration tons | × 3.5169 | kW |
|---|---|---|
| 1 TR | × 3.5169 | 3.52 kW |
| 5 TR | × 3.5169 | 17.58 kW |
| 20 TR | × 3.5169 | 70.34 kW |
| 100 TR | × 3.5169 | 351.7 kW |
| 500 TR | × 3.5169 | 1,758 kW |
How to convert refrigeration tons to kW
Multiply by 3.5169. The useful mental anchor is that a ton of refrigeration is roughly three and a half kilowatts, so a 100-ton chiller is about 350 kW and a domestic split unit rated at 1.5 tons is around 5 kW.
kW to refrigeration tons
Multiply by 0.28435, or divide by 3.5169. A 200 kW chiller is 56.9 tons. This direction is the one needed when European or Asian equipment rated in kilowatts has to be compared against American specifications in tons.
This is a rate, not a quantity
A ton of refrigeration is a unit of power — heat removed per unit of time — and so is the kilowatt it converts to. It is not a quantity of energy, and a 100-ton chiller does not consume 351.7 kilowatt-hours. Two further steps are needed and both are frequently skipped:
| What you want | What you need |
|---|---|
| Cooling capacity in kW | This conversion |
| Cooling energy delivered | × running hours → kWh of cooling |
| Electricity consumed | ÷ coefficient of performance (COP) |
That last step is where the emissions live. A 100-ton chiller delivers 351.7 kW of cooling, but at a coefficient of performance of 5 it draws only about 70 kW of electricity to do it — because a chiller moves heat rather than creating it, so the electrical input is a fraction of the thermal output. Converting capacity straight into an electricity figure overstates consumption several times over.
Why 12,000, and why the unit persists
Melting a short ton of ice absorbs about 288,000 BTU, and spreading that over a day gives 12,000 BTU per hour. When ice was delivered by the ton, that was a commercially meaningful way to describe how much cooling a machine replaced — and the convention outlived the trade that created it.
It persists because American HVAC equipment is still specified, sold and permitted in tons, while equipment elsewhere is rated in kilowatts and every energy calculation downstream is metric. A single project sourcing chillers internationally will meet both, which is the practical reason this conversion is needed at all. The underlying British thermal unit has its own complications — several competing definitions — which are set out on kWh to BTU; this page uses the International Table definition, as all of ours do.
Where this conversion is needed
- Equipment specification and tender comparison — matching American and European chiller ratings on one basis.
- Data centre cooling — capacity planning where IT load is in kilowatts and cooling plant is quoted in tons. See ASHRAE 90.4.
- Energy modelling — converting a nameplate capacity into the electrical demand a model needs, via the COP.
- Refrigerant inventory — system size is often the starting point for estimating charge, which is the input to refrigerant leakage reporting.
Cooling generates emissions two ways, and neither is this conversion. The electricity the plant draws is Scope 2 — size it via the COP, then use the Scope 2 electricity calculator, or the district heating and cooling calculator if the cooling is bought in. The refrigerant that leaks is Scope 1 and often the larger number for a given system — that is the refrigerant leakage calculator.
For the British thermal unit itself and its competing definitions, kWh to BTU. For cooling energy rather than capacity, kWh to MJ and kWh to GJ. For heat rather than cooling, GJ to MWh.
Frequently Asked Questions
Exactly 3.516853 kW, which is 12,000 British thermal units per hour. The mental anchor is three and a half kilowatts per ton, so a 100-ton chiller is about 350 kW of cooling capacity.
Multiply by 0.28435, or divide by 3.5169. So 200 kW of cooling is 56.9 tons. This is the direction needed when equipment rated in kilowatts has to be compared against American specifications.
No — that is its cooling output, not its electrical input. A chiller moves heat rather than creating it, so it delivers several times more cooling than the electricity it consumes. At a coefficient of performance of 5, a 100-ton chiller draws about 70 kW. Treating the capacity as consumption overstates it several times over.
Because it is the cooling you would get from melting one short ton of ice over twenty-four hours — about 288,000 British thermal units spread across a day, which comes to 12,000 per hour. When cooling was sold as delivered ice, that was a commercially meaningful comparison, and the unit outlived the trade.
Power — a rate of heat removal, which is why its metric partner is the kilowatt rather than the kilojoule. To get an energy figure you multiply by running hours, giving kilowatt-hours of cooling delivered; to get electricity consumed you then divide by the coefficient of performance.
Convert capacity to kilowatts, divide by the coefficient of performance to get electrical demand, multiply by running hours for consumption, then apply a grid emission factor — that is the Scope 2 side. Separately, refrigerant leakage is Scope 1 and is often the larger figure for a given system, so a cooling assessment that only counts electricity is usually incomplete.
A typical split unit rated at 1.5 tons is about 5.3 kW of cooling, and a 2-ton unit about 7 kW. Note that these are cooling outputs — the electrical rating on the same unit will be substantially lower, and it is the electrical figure that appears on a bill.
Yes. Twelve thousand British thermal units per hour is a definition, the International Table British thermal unit is defined as exactly 1,055.05585262 joules, and the hour is 3,600 seconds — so 3.516853 kW carries no measurement uncertainty. The only ambiguity anywhere near it is which British thermal unit is meant, and every conversion on this site uses the International Table one.