What this converter does
This converter turns mechanical horsepower into BTU per hour and back instantly. One horsepower is about 2,544 BTU/hr, the figure used to match motor output to a heating or cooling load. Type a value and read the result as you type.
It also covers kilowatts and tons of refrigeration. For motor current, see the HP to Amps converter.
The units it covers
These are all units of power, each with a fixed value in kilowatts, so any pair converts through the kilowatt.
View all units & their values
| Unit | Symbol | Value | Mainly used |
|---|---|---|---|
| Horsepower (mechanical) | hp | 0.7457 | Engines, motors, machinery |
| BTU per hour | BTU/hr | 0.0002931 | Heating and cooling loads |
| Kilowatt | kW | 1 | SI power unit |
| Ton of refrigeration | TR | 3.5169 | Air-conditioning capacity |
The formula
Each unit has a fixed value in kilowatts, so converting between any two is one multiplication:
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 5 hp to BTU/hr.
1 hp = 2,544.43 BTU/hr5 × 2,544.43 = 12,722 BTU/hrSo a 5 hp motor equals about 12,722 BTU/hr of heat.
The units in this example
The imperial power unit, 745.7 watts, used for engines, motors and machinery.
- 1 hp ≈ 2,544 BTU/hr
- 1 hp = 0.7457 kW
- 1 hp ≈ 0.212 TR
- 1 hp = 745.7 W
A rate of heat energy, standard for HVAC heating and cooling capacity in the US.
- 1,000 BTU/hr ≈ 0.393 hp
- 12,000 BTU/hr = 1 TR
- 3,412 BTU/hr = 1 kW
- 2,544 BTU/hr ≈ 1 hp