hp
Definition
Mechanical horsepower equals 745.7 watts — James Watt's 1782 definition based on horse labor. Used in US car engines, aircraft and some industrial equipment. US muscle cars quote hp; European cars usually kW or PS.
Common uses
- US car and motorcycle engine ratings
- Lawn mower and small engine specs
- US pump and compressor ratings
🌍 Real-world scale
Base Ford Mustang: ~310 hp. Lawn mower: 5 hp. Average car: 150–200 hp.
Convert from mechanical horsepower
7 conversionsMechanical Horsepower to Watt1 hp = 745.7 WMechanical Horsepower to Kilowatt1 hp = 0.7457 kWMechanical Horsepower to Megawatt1 hp = 0.0007457 MWMechanical Horsepower to Metric Horsepower1 hp = 1.01387 PSMechanical Horsepower to BTU per Hour1 hp = 2,544.43 BTU/hMechanical Horsepower to Foot-Pound per Second1 hp = 550 ft·lbf/sMechanical Horsepower to Volt-Ampere1 hp = 745.7 VA
Convert to mechanical horsepower
7 conversionsWatt to Mechanical Horsepower1 W = 0.001341 hpKilowatt to Mechanical Horsepower1 kW = 1.34102 hpMegawatt to Mechanical Horsepower1 MW = 1,341.02 hpMetric Horsepower to Mechanical Horsepower1 PS = 0.9863 hpBTU per Hour to Mechanical Horsepower1 BTU/h = 0.000393 hpFoot-Pound per Second to Mechanical Horsepower1 ft·lbf/s = 0.001818 hpVolt-Ampere to Mechanical Horsepower1 VA = 0.001341 hp
Tips
- 1 hp = 745.7 W = 0.7457 kW.
- US car ads quote hp; European ads quote kW or PS.
- Metric horsepower (PS) differs by ~1.4% — be aware.
Common mistakes
- Assuming hp and PS are identical — 1.4% difference.
- Using horsepower for electrical devices — watts more appropriate.
- Confusing horsepower at engine flywheel vs wheel (transmission losses).
FAQ about the mechanical horsepower
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