What this converter does
This converter turns cooling capacity in BTU/hr into tons of refrigeration and back instantly. One ton equals 12,000 BTU/hr — the heat to melt a ton of ice in a day — so it is the standard way to read AC and chiller sizes. Type a value and read it as you type.
It also covers kilowatts and kcal/h. For the metric power side of a chiller, see the tons to kW converter.
The units it covers
These are cooling-capacity units, each with a fixed value in kilowatts of heat, so the conversion is a single multiplication.
View all units & their values
| Unit | Symbol | Value | Mainly used |
|---|---|---|---|
| British thermal unit per hour | BTU/hr | 0.0002931 | US cooling capacity |
| Ton of refrigeration | TR | 3.5169 | AC and chiller ratings |
| Kilowatt | kW | 1 | Metric thermal power |
| Kilocalorie per hour | kcal/h | 0.001163 | Legacy metric cooling |
The formula
Each unit has a fixed value in kilowatts of heat, so converting between any two is one step:
result = value × factor_from ÷ factor_toWhere:
- value = the number you typed
- factor_from = the “from” unit’s value in kW
- factor_to = the “to” unit’s value in kW
Worked example
Convert 18,000 BTU/hr to tons.
1 ton = 12,000 BTU/hr18,000 ÷ 12,000 = 1.5 tonsSo an 18,000 BTU/hr unit is a 1.5-ton air conditioner.
The units in this example
The US measure of cooling (or heating) capacity, printed on AC nameplates.
- 12,000 BTU/hr = 1 ton
- 1 BTU/hr = 0.0000833 ton
- 1 BTU/hr = 0.000293 kW
- 24,000 BTU/hr = 2 tons
The cooling to freeze a short ton of water in 24 hours — the standard AC/chiller size unit.
- 1 ton = 12,000 BTU/hr
- 1 ton = 3.517 kW
- 1 ton = 3,024 kcal/h
- 2 tons = 24,000 BTU/hr