Unit Conversions
Horsepower vs Kilowatts: Understanding Power Units
Learn the difference between horsepower and kilowatts, the conversion factor, and why car manufacturers use different units in different markets.
When shopping for a car in Europe, you see power listed in kilowatts (kW). In the US, it's horsepower (hp). These are both units of power — the rate at which energy is produced or consumed — just in different measurement traditions.
Where 'Horsepower' Comes From
James Watt invented the term in the late 18th century to market his steam engines. He needed a way to compare his engines to the horses they replaced. He measured how much work a mill horse could do and defined 1 horsepower as 550 foot-pounds per second (33,000 foot-pounds per minute). The unit stuck.
The Conversion
1 mechanical horsepower = 0.745699872 kilowatts. Or: 1 kW = 1.341 hp. A 150 hp engine produces about 112 kW. A 200 kW motor develops about 268 hp.
Common Car Power Levels
- Economy car: ~75 hp (56 kW)
- Mid-size sedan: ~150–200 hp (112–149 kW)
- Sports car: ~300–500 hp (224–373 kW)
- Supercar: 500–1,000+ hp (373–746+ kW)
Electric Vehicles and Power
Electric vehicle manufacturers often list power in both kW and hp. A Tesla Model 3 Long Range produces about 358 hp (267 kW). Unlike combustion engines, electric motors deliver maximum torque instantly — so power figures translate differently to real-world driving feel.