Horsepower to Watts Converter
Convert mechanical (imperial) horsepower to watts. 1 hp = 745.7 W.
Result
Watts
74,569.99 W
74.570 kW.
- Conversion factor745.6999 W/hp
- kW74.5700
- BTU/hr254,443.2
Step-by-step
- 100 hp × 745.6998715822702 = 74,569.99 W.
How to use this calculator
- Enter horsepower.
- Pick HP type (mechanical for US cars, metric for Euro cars, electrical for motor specs).
- Read watts and kW.
About this calculator
"Horsepower" actually has three definitions used in different contexts. Mechanical (or imperial) is 745.7 W — used for cars in the US. Metric (PS, Pferdestärke, used in Europe) is 735.5 W. Electrical is exactly 746 W — used by motor manufacturers. The differences are small (<2%) but matter for precise conversions.
Frequently asked
Historical accident. Watt defined his 1 hp ≈ 33,000 ft-lbf/min (mechanical). Metric horsepower came from continental Europe at 75 m·kgf/s. Electrical horsepower was rounded for motor specifications.
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