What Is the Watts to Horsepower Calculator?
This tool converts electrical or mechanical power expressed in watts (W) into horsepower (HP). The watt is the SI unit of power, while horsepower is a traditional unit still widely used to rate engines, motors, pumps, and appliances. Because several definitions of horsepower exist, this calculator lets you choose the one you need.
How to Use It
Enter the power value in watts, select the horsepower type (mechanical, metric, or electric), and the calculator returns the equivalent horsepower instantly. Mechanical horsepower (745.7 W) is the most common in the US and UK, metric horsepower (735.49875 W, also called PS or CV) is common in Europe for engine ratings, and electric horsepower (746 W) is used for electric motors.
The Formula Explained
The core conversion is:
$$\text{HP} = \frac{\text{W}}{745.7}$$
One mechanical horsepower equals 745.7 watts. To convert, simply divide the power in watts by the chosen conversion factor. To go the other way, multiply horsepower by 745.7 to get watts.
Worked Example
Suppose a motor is rated at 1,000 watts. Using mechanical horsepower: $$\text{HP} = \frac{1000}{745.7} = 1.3410 \text{ HP}$$ So a 1 kW motor produces roughly 1.34 mechanical horsepower.
FAQ
How many watts are in 1 horsepower? Mechanical horsepower is 745.7 W, metric horsepower is about 735.5 W, and electric horsepower is exactly 746 W.
Which horsepower should I use? Use mechanical for general US/UK engine ratings, metric (PS) for European car specs, and electric for electric motors.
Is kW the same as watts? No — 1 kilowatt = 1,000 watts. Multiply kW by 1,000 before entering, or enter the watt value directly.
