Which formula correctly converts horsepower to kilowatts?

• A. PkW = HP × 0.5
• B. PkW = HP × 0.746
• C. PkW = HP × 1.0
• D. PkW = HP ÷ 0.746

Answer: (B)

Converting horsepower to kilowatts uses the standard factor that defines how many kilowatts are in one horsepower. A mechanical horsepower is defined as about 745.7 watts, so 1 HP is roughly 0.746 kW. To get kilowatts from horsepower, multiply the horsepower value by 0.746: PkW = HP × 0.746. This is the correct approach because it directly scales the unit from horsepower to kilowatts using the established conversion.

If you try the other forms, they don’t match the real relationship. Multiplying by 0.5 would give too small a value, multiplying by 1.0 would leave you numerically equal to horsepower (not in kilowatts), and dividing by 0.746 would inflate the result beyond the actual kilowatts. For example, 100 HP yields about 74.6 kW with the correct factor, whereas the other forms produce 50 kW, 100 kW, or about 134 kW.