How many watts equals one horsepower?

How many watts equals one horsepower?

• A. 700
• B. 746
• C. 740
• D. 800

Answer: (C)

Power is measured in watts, and horsepower is a traditional unit used for engines. By definition, one horsepower equals 550 foot-pounds of work per second. To convert to watts, use that 1 foot-pound is 1.355818 joules, so 550 × 1.355818 ≈ 745.7 joules per second, i.e., 745.7 watts. In practice this is commonly rounded to 746 watts. There’s also a metric horsepower definition (about 735.5 watts), but for the standard horsepower often used in HVAC and mechanical contexts, 746 watts per horsepower is the typical figure.

Power is measured in watts, and horsepower is a traditional unit used for engines. By definition, one horsepower equals 550 foot-pounds of work per second. To convert to watts, use that 1 foot-pound is 1.355818 joules, so 550 × 1.355818 ≈ 745.7 joules per second, i.e., 745.7 watts. In practice this is commonly rounded to 746 watts. There’s also a metric horsepower definition (about 735.5 watts), but for the standard horsepower often used in HVAC and mechanical contexts, 746 watts per horsepower is the typical figure.