Horsepower to Watts Converter Formula

Understand the math behind the horsepower to watts converter. Each variable explained with a worked example.

Use the Horsepower to Watts Converter

Formulas Used

Watts

watts = hp * 745.7

Kilowatts

kilowatts = hp * 0.7457

BTU per Hour

btu_per_hr = hp * 2544.43

Variables

VariableDescriptionDefault
hpHorsepower(hp)150

How It Works

How to Convert Horsepower to Watts

Formula

Watts = Horsepower × 745.7

Kilowatts = Horsepower × 0.7457

One mechanical horsepower equals 745.7 watts. This is the standard mechanical (or imperial) horsepower defined by James Watt. Note that metric horsepower (PS) is slightly different at 735.5 watts.

Worked Example

Convert 150 horsepower to watts and kilowatts.

hp = 150
  1. 01Watts = 150 × 745.7 = 111,855 W
  2. 02Kilowatts = 150 × 0.7457 = 111.855 kW
  3. 03BTU/hr = 150 × 2544.43 = 381,664.5 BTU/hr

Ready to run the numbers?

Open Horsepower to Watts Converter