Whether you are reading the specifications of a new electric car, comparing industrial pump motors, or browsing car specifications from different countries, you will often find power ratings expressed in different units. The two most common units of power are the kilowatt (kW) and the horsepower (HP). Converting between these units requires understanding which type of horsepower is being referenced, as several standards exist worldwide.
A kilowatt is a universal metric unit of power defined by the International System of Units (SI). It measures the rate of energy transfer and is equal to 1,000 watts, or 1,000 joules per second. Because it is a standardized metric unit, it is used globally for rating electrical motors, solar panels, and modern car engines in many regions.
Horsepower, on the other hand, is an older unit of power that originated during the industrial revolution. In the English system, mechanical horsepower is defined as 550 foot-pounds per second, which equals approximately 745.7 watts. To perform basic unit changes for other physical properties, you can explore our translating measuring units tool. For checking basic calculation steps, use our everyday calculation helper.
When converting power, it is helpful to note that not all horsepower is the same:
To round converted values to a clean layout, you can check our decimal rounding utility.
Understanding these conversions is crucial for comparing international automotive specifications. For example, European car reviews might rate an engine in PS or kilowatts, while American sites report the output in mechanical horsepower.
Similarly, industrial electric motors are often rated in kilowatts in global trade but described in horsepower on North American workshop labels. Converting these ratings ensures you purchase the correct motor capacity for your machinery. To calculate engine power directly from rotational speed and torque, visit our engine torque and rotation speed solver. You can also view trip metrics using our vehicle fuel economy monitor.
Let us convert a modern electric car's power rating of 200 kilowatts (kW) into mechanical horsepower (HP).
To convert kilowatts to mechanical horsepower, multiply the kilowatt value by the conversion factor 1.341: 200 × 1.341 = 268.2. Therefore, a 200 kW motor produces approximately 268 horsepower.
If we were converting 300 horsepower to kilowatts instead, we would multiply by 0.7457: 300 × 0.7457 = 223.71 kW. This demonstrates how easily power ratings translate across different machinery standards.