About this calculator
A 1.5-ton AC is rated by its cooling power, not by the electricity it uses, which is much lower.
How to use it
- Enter the value.
- Choose the unit it is in and the unit you want.
- Read the result, or see every unit in the table.
The formula
Result = value × (watts in the “from” unit) ÷ (watts in the “to” unit)
- 1 hp
- 745.7 W
- 1 PS
- 735.5 W
- 1 ton of refrigeration
- 3,517 W of cooling
Worked example
A 1.5-ton air conditioner
- Cooling power = 1.5 × 3.517 = 5.28 kW, or 18,000 BTU/h.
- A typical 5-star unit uses about a third of that in electricity.
What the result means
The factors are exact international definitions, so results are as accurate as the digits shown.
Assumptions
- Mechanical horsepower and the standard refrigeration ton.
Limitations
- AC power use depends on its star rating; see the label.
Frequently asked questions
How many kW is 1 HP?
0.7457 kW.
How much electricity does a 1.5-ton AC use?
Usually about 1.2 to 1.8 kW, depending on the model.
What is PS?
Metric horsepower, used for many car engines: 735.5 W.
Last reviewed on 3 October 2026. Found a mistake? Tell us.