⚖️ Comparison · Updated for 2026
HP (Horsepower) vs PS (Pferdestärke) / kW
Side-by-side comparison, when-to-use-each guide, and instant conversion. Reviewed for 2026.
Quick answer: 1 mechanical HP = 745.7 W. 1 metric PS = 735.5 W. 1 kW = 1.341 HP = 1.36 PS. UK/US car spec sheets use HP; European spec sheets use PS or kW. A '300 PS' German car has 296 HP — a small but real 1.4% gap. Electric cars are now consistently rated in kW.
Decision guide — when to use which
Use HP (Horsepower) when…
UK and US car marketing, motorbike specs everywhere, lawnmower specs in the UK.
Use PS (Pferdestärke) / kW when…
German, French, Italian car marketing (PS); all EU type-approval; all electric vehicle specs (kW).
📊 Side-by-side comparison
| Aspect | HP (Horsepower) | PS (Pferdestärke) / kW |
|---|---|---|
| Definition | 1 HP = 745.7 W (mechanical) | 1 PS = 735.5 W; 1 kW = 1000 W |
| Origin | James Watt, 1782 (Birmingham brewery horse) | Metric horsepower; SI watt |
| UK car ad | '300 bhp' | Sometimes 'kW' in small print |
| German car ad | Sometimes HP in export | '300 PS' / '221 kW' |
| EV / electric motor | Rarely HP | Always kW (sometimes PS) |
Frequently asked
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Is HP the same as BHP?
In modern usage, basically yes. BHP (brake horsepower) is the power measured at the engine's output shaft using a brake dynamometer. Most modern HP figures are effectively BHP. The distinction is largely historical.
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Why do German cars use PS?
Metric horsepower (Pferdestärke = 'horse strength') was defined in 1907 to align with the watt. It's slightly smaller than mechanical HP. Continental European manufacturers standardised on PS in the 1920s and never switched.
Reviewed for 2026. All conversion factors and historical references verified against official sources (ISO standards, government weights & measures legislation, IEC technical specifications). Built by a UK-based qualified primary teacher and FA Level 2 coach as part of 247QuickTools' free utility-tools project. We don't sell SEO links or accept paid placements in this content.