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Horsepower to watts converter

Convert horsepower to watts, both ways.

Type a power in horsepower and read the exact watts, or type watts to convert back. The result updates live, with kilowatts, metric horsepower and real-engine context and a one-click copy.

Your power

HP
W

Edit either box. The formula is W = HP times 745.7, and HP = W divided by 745.7 (mechanical horsepower).

200 HP in watts
0 W
149140 W
Share of a 250 kW electric car motor covered59.7%
Tesla Model 3 LR motor = 250,000 W = 335.3 HP (full bar)200
Kilowatts
149.14
Metric HP (PS)
202.77
BTU per hour
508887
Power context
a midsize car engine

What this means

    Common engines in kilowatts

    kW Each bar shows the kilowatt equivalent of a common engine or motor rating, from a 5 HP lawn mower to a 450 HP performance EV. Every height is the horsepower times 745.7, divided by 1000.

    Power milestones

    1 HP
    745.7 W
    The definition of one mechanical horsepower, the rate a draft horse can sustain.
    100 HP
    74.57 kW
    A small city car engine, the entry point of modern motoring.
    500 HP
    372.85 kW
    Supercar territory, or a serious industrial electric motor.
    1000 HP
    745.7 kW
    Hypercar output, close to three quarters of a megawatt.

    Common HP to watts values

    HorsepowerWattsKilowattsWhere you see it

    How the conversion works

    Conversion Factor

    1 mechanical horsepower equals 745.7 watts. Multiply HP by 745.7 to get watts, or by 0.7457 to get kW. Useful for converting traditional engine ratings to electrical equivalents.

    Engine and Motor Comparison

    Car engines are rated in HP in the US, kW in Europe. Comparing a 200 HP gas engine to a 150 kW electric motor (= 201 HP) puts them on equal footing.

    Reference Values

    1 HP = 746 W = 0.746 kW. 100 HP = 74.6 kW. 200 HP = 149.1 kW. 500 HP = 372.8 kW. 1000 HP = 745.7 kW.

    Common questions

    200 HP in kW?

    200 HP = 149.1 kW.

    Why James Watt picked 'horsepower'?

    Watt compared steam engines to draft horses for marketing. 1 HP was the rate at which a strong draft horse could sustain work for a full day.

    Mechanical vs electrical HP?

    Mechanical = 745.7 W. Electrical = 746 W. Metric HP (PS) = 735.5 W. All slightly different, all close.

    All conversion runs in your browser. Nothing is uploaded. 1 mechanical horsepower is defined as 550 foot-pounds per second, which is 745.6999 watts, so these results are precise, not approximate. Electrical HP (746 W) and metric HP (735.5 W) differ slightly.