Power Converter
Enter a value to instantly convert between power units.
Power conversions come up most often when comparing engine or motor specifications given in horsepower against electrical power ratings in watts or kilowatts — for example, comparing a car's horsepower to an electric motor's kilowatt rating, or understanding how many watts an appliance draws relative to a generator's horsepower rating. Power measures the *rate* of energy use or production (energy per unit time), which distinguishes it from the energy category — a power conversion tells you how fast energy is being transferred, not how much total energy is involved.
1 Kilowatt = 1.341 Horsepower (mech)
Key Formulas
Kilowatt → Horsepower (mech)
hp = kW × 1.34102Horsepower (mech) → Kilowatt
kW = hp × 0.7457Watt → Kilowatt
kW = W × 0.001Kilowatt → Watt
W = kW × 1000Popular Conversions
All Power Conversions
About Power Conversions
History & Background
The watt, the SI unit of power, is named after James Watt, the Scottish engineer whose improvements to the steam engine were central to the Industrial Revolution — fittingly, since horsepower (the unit Watt himself helped popularize) was originally defined by comparing steam engine output to the power of a horse, in order to market early engines to customers who needed a familiar reference point. There are actually several slightly different definitions of horsepower (mechanical/imperial horsepower, metric horsepower, and electrical horsepower), which differ by a few percent — most automotive contexts use mechanical horsepower (745.7 watts), but European vehicle specifications sometimes use metric horsepower (735.5 watts, abbreviated PS), a small but real difference when comparing specs across regions.
How to Use This Converter
Select your starting and target power units and enter a value for an instant conversion. When comparing horsepower figures between US/UK and European sources, be aware that 'hp' may refer to mechanical horsepower or metric horsepower (PS) depending on the source — the difference is small (about 1.4%) but can matter when comparing precise specifications.
Frequently Asked Questions
What's the difference between horsepower and metric horsepower (PS)?
Mechanical (imperial) horsepower is defined as 745.7 watts, while metric horsepower (PS, from the German 'Pferdestärke') is defined as 735.5 watts — about 1.4% smaller. European car specifications often use PS, while US specifications typically use mechanical horsepower. The difference is small but means a car advertised as '300 PS' has slightly less power than one advertised as '300 hp.'
How many watts does a typical horsepower convert to?
1 mechanical horsepower = 745.7 watts (about 0.75 kW). This is useful for comparing, for example, a gasoline engine's horsepower rating to an electric motor's kilowatt rating — a 100 hp engine is roughly equivalent in power output to a 75 kW electric motor, though efficiency, torque characteristics, and usable power band differ significantly between the two.
Why do appliance labels show watts but generators show both watts and horsepower?
Electrical appliances draw power measured directly in watts (an electrical quantity), while generators are often built around an internal combustion engine, whose mechanical output is traditionally rated in horsepower — but the generator's electrical output is rated in watts, since that's what determines which appliances it can run. Both figures appear because they describe different parts of the device: the engine (horsepower) and the electrical output (watts).
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