Convert between watts, kilowatts, horsepower and BTU/h.
Converted instantly in your browser.
How do you convert watts to horsepower and other power units?
Each value is converted to watts, then to the target unit; for example, 1 mechanical horsepower = 745.7 W and 1 metric horsepower (PS) = 735.5 W. So 100 hp = 74.57 kW = 254,407 BTU/h. Mechanical and metric horsepower differ slightly, and BTU/h is common for heating and air-conditioning ratings.
Understanding your result
Mechanical (imperial) horsepower and metric horsepower (PS) differ slightly. BTU/h is common for heating and air-conditioning ratings.
Formula and method
Each value is converted to watts, then to the target unit. For example, 1 mechanical horsepower = 745.7 W and 1 metric horsepower (PS) = 735.5 W.
Worked example
100 hp = 74.57 kW = 254,407 BTU/h.
How to use this tool
- Enter the power value.
- Choose the units to convert from and to.
- Read the result and the full unit table.
Common mistakes to avoid
- Mixing up energy (watt-hours) with power (watts) — power is the rate of energy use.
About the Power Converter
Convert power between watts, kilowatts, horsepower and BTU per hour. Enter a value and see every unit at once.
Explore all Unit Converters tools
Frequently asked questions
How many kW is 1 hp?
One mechanical horsepower is about 0.7457 kW.
What is the difference between hp and PS?
PS is metric horsepower (735.5 W); mechanical hp is 745.7 W, so they differ by about 1.4%.