Pferdestärken

Pferdestärke, commonly abbreviated PS, is the metric unit of power known as metric horsepower. By definition, 1 PS equals 75 kilogram-force metres per second (75 kgf m/s), the power required to move a 75-kilogram mass by 1 meter in one second against gravity. This is equal to 735.49875 watts, or about 0.7355 kilowatts.

The unit originated in the late 19th and early 20th centuries alongside the broader adoption of metric measurements in engineering. It was standardized for practical use in German-speaking countries and many parts of Europe. Although the SI-recognized kilowatt is now common, PS remains familiar in car labels, engine specifications, and consumer advertising in Germany, Austria, Switzerland, and several other markets.

Conversions to other units are as follows: 1 PS ≈ 0.7355 kW; 1 kW ≈ 1.3596 PS; 1 PS ≈ 0.98632 mechanical horsepower, while 1 mechanical horsepower ≈ 1.01387 PS. Because horsepower definitions differ between regions, PS and hp are not always interchangeable in practice, and exact values depend on the measurement standard used.

Usage and context: In automotive and mechanical engineering, PS is used to express engine output, typically referring to power at the engine crankshaft or as stated by manufacturers. While kilowatts increasingly replace PS in many technical documents, PS remains common in European car specifications and advertisements, reflecting historical usage and regional familiarity.