How is horsepower calculated?
1 Answers
1 imperial horsepower = 0.746 kilowatts (kW), 1 metric horsepower = 0.735 kilowatts (kW); Power (W) = 2π × Torque (N-m) × Speed (rpm)/60; Simplified calculation becomes: Power (kW) = Torque (N-m) × Speed (rpm)/9549. Horsepower is a unit of engine power, representing the engine's working capacity per unit of time. More details are as follows: 1. Horsepower is a commonly used unit of power measurement in engineering. It generally refers to metric horsepower rather than imperial horsepower. The definition of metric horsepower is entirely artificial, taking a value very close to imperial horsepower. 2. It is defined that 1 metric horsepower is the work done to lift 75 kilogram-meters in 1 second. That is: 1 metric horsepower = 75 kilogram-force meters/second = 735 watts. Countries like the United Kingdom and the United States use imperial horsepower. 1 imperial horsepower equals 550 foot-pounds/second, equivalent to 745.7 watts. 3. In the late 18th century, British physicist James Watt (1736–1819), to measure the power of newly manufactured steam engines, defined horsepower as the work required to lift a 1000-pound weight by 33 feet in 1 minute. This is imperial horsepower, denoted by the letter HP. 4. 1 imperial horsepower = 1.0139 metric horsepower. There is no specific letter for metric horsepower, and the value of 1 metric horsepower differs from that of 1 imperial horsepower. Horsepower has been abolished in China's legal measurement units.
