Watts to Horsepower Converter

To convert a measurement in watts to horsepower, multiply the value by 0.00134102209. The conversion factor comes from the relationship between both units and the watt.

For example, to convert 5 W to horsepower: 5 × 0.00134102209 = 0.006705110448 hp.

A watt is the SI derived unit of power, equal to one joule of energy per second (1 J/s). Named after Scottish engineer James Watt, whose steam-engine improvements powered the Industrial Revolution. The watt became the SI unit of power in 1960 and now measures everything from light bulbs to power plants.

Common uses of watts include: Light bulb and appliance ratings; Electronic device power consumption; Audio amplifier output; Scientific and electrical calculations.

Mechanical horsepower (hp) is a unit of power equal to about 745.7 watts, originally defined to compare engine output to the work of draft horses. James Watt coined horsepower in the 1780s to market his steam engines against the horses they replaced. Mechanical horsepower remains the dominant unit for engine power in the United States.

Common uses of horsepower include: Car and motorcycle engine ratings (US); Lawn mowers and power tools; Marine and outboard motors; Comparing engine performance.

Cyclists, hobbyists, and engineers convert watts to horsepower to gauge real output. A trained sprinter can briefly hit 1,500 W, about two horsepower, and small motors rated in watts are easier to compare against tools quoted in horsepower once converted.

Here are some common values converted:

1 W = 0.00134102209 hp 5 W = 0.006705110448 hp 10 W = 0.013410220896 hp 50 W = 0.06705110448 hp 100 W = 0.13410220896 hp