Is PS the same as horsepower?

Not exactly. PS (Pferdestärke, German for 'horse strength'; also written CV in French and Italian) is metric horsepower, defined as 75 kgf·m/s — about 735.5 W. Mechanical (imperial) horsepower is defined differently, at 550 ft·lbf/s — about 745.7 W. PS is roughly 1.4% smaller than hp.

How do you convert PS to hp?

Multiply PS by 0.98632 (735.49875 / 745.69987158227022) to get mechanical horsepower. A car listed at 150 PS is about 147.9 hp.

Why does the difference between hp and PS matter?

For most consumer purposes the roughly 1.4% gap is minor, but it matters when comparing spec sheets across markets — a European car listed at 150 PS is not identical to a US car listed at 150 hp; the PS figure is the slightly smaller unit, so the PS car has marginally less power than the number alone suggests.

Which countries typically use PS or CV instead of hp?

Metric horsepower under the name PS is standard in Germany and much of continental Europe; the same unit is called CV in France and Italy. It typically appears in these markets' vehicle spec sheets and registration documents.

Guide

HP vs PS: mechanical vs metric horsepower compared

Mechanical horsepower (hp) is defined as 550 ft·lbf/s, about 745.7 W. Metric horsepower (PS in German, CV in French and Italian) is defined as 75 kgf·m/s, about 735.5 W — roughly 1.4% smaller.

By Buğra SözeriPublished September 25, 2026

Horsepower isn't one unit — it's a family of similarly named but numerically different units, and the two that show up most often on car spec sheets are mechanical (imperial) horsepower, used in the US, and metric horsepower, known as PS in Germany and CV in France and Italy. Both trace back to the same 18th-century idea of comparing engine output to a horse's work rate, but each was formalized against a different base-unit system, and they don't match exactly.

The two definitions

Unit	Definition	Value in watts
Mechanical horsepower (hp)	550 ft·lbf/s	745.69987158227022 W
Metric horsepower (PS / CV)	75 kgf·m/s	735.49875 W

The gap between them — about 10.2 W, or roughly 1.4% — comes entirely from the two units being derived from different base measurement systems (imperial foot-pounds-force vs metric kilogram-force-meters), not from measuring a different physical quantity.

Reference values

Mechanical hp	Metric PS
100 hp	≈ 101.4 PS
150 hp	≈ 152.1 PS
200 hp	≈ 202.8 PS
300 hp	≈ 304.1 PS

Reading a spec sheet correctly

When a car, motorcycle, or engine's power is quoted only as a bare number without a stated unit, checking whether it's listed in a market that uses hp or PS matters more than it might seem — a "150" on a German spec sheet almost always means 150 PS (about 147.9 hp), not 150 hp outright. The practical difference is small at typical passenger-vehicle power levels, but it compounds into a meaningfully larger gap on higher-output engines, and it's the kind of unit mismatch that shows up when directly comparing horsepower figures pulled from spec sheets written for different markets.

Frequently asked questions

Is PS the same as horsepower?: Not exactly. PS (Pferdestärke, German for 'horse strength'; also written CV in French and Italian) is metric horsepower, defined as 75 kgf·m/s — about 735.5 W. Mechanical (imperial) horsepower is defined differently, at 550 ft·lbf/s — about 745.7 W. PS is roughly 1.4% smaller than hp.
How do you convert PS to hp?: Multiply PS by 0.98632 (735.49875 / 745.69987158227022) to get mechanical horsepower. A car listed at 150 PS is about 147.9 hp.
Why does the difference between hp and PS matter?: For most consumer purposes the roughly 1.4% gap is minor, but it matters when comparing spec sheets across markets — a European car listed at 150 PS is not identical to a US car listed at 150 hp; the PS figure is the slightly smaller unit, so the PS car has marginally less power than the number alone suggests.
Which countries typically use PS or CV instead of hp?: Metric horsepower under the name PS is standard in Germany and much of continental Europe; the same unit is called CV in France and Italy. It typically appears in these markets' vehicle spec sheets and registration documents.

Sources & references

Authoritative references cited by this piece. Verified by Buğra Sözeri on the dates shown and re-checked at every deploy.

BIPM — SI Brochure, 9th edition (watt as the coherent SI unit both horsepower variants are defined against) — Reference for the watt definition used to fix both horsepower variants precisely(as of 2026-09-25)