Horsepower and watts are both units used to measure power, with various definitions depending on the context. Mechanical (or imperial) horsepower is commonly used to quantify the power output of engines and is defined as approximately 745.7 watts. In electrical contexts, one horsepower is exactly 746 watts. The metric horsepower, often used in Europe, is defined as approximately 735.5 watts. To convert horsepower to watts, multiply the horsepower value by the appropriate conversion factor: 745.7 for mechanical horsepower, 746 for electrical horsepower, or 735.5 for metric horsepower. For example, to convert 10 mechanical horsepower to watts, multiply 10 by 745.7, resulting in 7,457 watts. Conversely, to convert watts to horsepower, divide the wattage by the corresponding conversion factor. These conversions are essential in fields like automotive engineering, electrical engineering, and various industrial applications where understanding power output and consumption is crucial.