Convert from watt to horsepower [international]

Unit Definition (watt)
The watt is the SI unit of power. Power is the rate at which work is done, or (equivalently) the rate at which energy is expended. One watt is equal to a power rate of one joule of work per second of time. This unit is used both in mechanics and in electricity, so it links the mechanical and electrical units to one another. In mechanical terms, one watt equals about 0.001 341 02 horsepower (hp) or 0.737 562 foot-pound per second (lbf/s). In electrical terms, one watt is the power produced by a current of one ampere flowing through an electric potential of one volt. The name of the unit honors James Watt (1736-1819), the British engineer whose improvements to the steam engine are often credited with igniting the Industrial Revolution.

Unit Definition (horsepower [international])
Horsepower (hp or HP) is the name of several non-metric units of power. In scientific discourse, the term "horsepower" is rarely used because of its various definitions and the already existent SI unit for power, the watt (W). However, use of the term "horsepower" persists as a legacy in many languages and industries, particularly as a unit of measurement of the maximum power output of internal-combustion engines of automobiles; and often of trucks, buses, and ships. The use of 'HP' is being slowly replaced by kW (kilowatt) and MW (megawatt).