How is the horsepower of a car calculated?

[JulietteMarie]

The calculation method for a car's horsepower: Horsepower is calculated from torque, and the formula is; power (kw) torque (n-m) multiplied by speed (rpm) divided by 9549. The horsepower of an engine refers to the size of the engine's output capability (work done), that is, the output power, which is a very important parameter for measuring car performance and is used to evaluate engine performance. Horsepower, torque, and speed are essentially three interrelated parameters. The need for horsepower in a car is mainly for better handling performance and good acceleration performance, but horsepower is not the only parameter. There are many other factors that affect car performance, such as torque, power ratio, etc.