Convert Mechanical Horsepower to Metric Horsepower (hpPS)

Horsepower is the American and British unit for car engines, motorcycles, and traditional mechanical power ratings.

1.01387
1 hp1.01387 PSNIST · BIPM accuracy

Mechanical Horsepower to Metric Horsepower Conversion Table

10 common values
Mechanical HorsepowerMetric Horsepower
1 hp1.01387 PS
5 hp5.069348 PS
10 hp10.138697 PS
50 hp50.693483 PS
100 hp101.38697 PS
500 hp506.93483 PS
1,000 hp1,013.8697 PS
5,000 hp5,069.3483 PS
10,000 hp10,138.697 PS
50,000 hp50,693.483 PS

How to Convert Mechanical Horsepower to Metric Horsepower Manually

Step by Step

Converting mechanical horsepower to metric horsepower is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.

  1. 1
    Take your value in mechanical horsepower
    Start with the number of mechanical horsepower (hp) you want to convert.
  2. 2
    Multiply by 1.01387
    The conversion factor from hp to PS is 1.01387. Multiply your value by this number.
  3. 3
    Read the result in metric horsepower
    The result is your value in metric horsepower (PS).
Practical Examples
1 hp
equals
1.01387 PS
5 hp
equals
5.069348 PS
10 hp
equals
10.138697 PS
25 hp
equals
25.346742 PS
100 hp
equals
101.38697 PS

Formula

Multiply the value in mechanical horsepower by 1.01387. For the reverse direction, multiply by 0.98632.

ForwardPS = hp × 1.01387
Reversehp = PS × 0.98632
Example: 10 hp × 1.01387 = 10.138697 PS

Tips

Use these in everyday conversions
  • 1 hp = 745.7 W = 0.7457 kW.
  • US car ads quote hp; European ads quote kW or PS.
  • Metric horsepower (PS) differs by ~1.4% — be aware.

Common Mistakes

Avoid these
  • Assuming hp and PS are identical — 1.4% difference.
  • Using horsepower for electrical devices — watts more appropriate.
  • Confusing horsepower at engine flywheel vs wheel (transmission losses).

About Mechanical Horsepower and Metric Horsepower

What is the Mechanical Horsepower?

Horsepower (hp) equals exactly 745.6998715822702 watts (mechanical horsepower) and is the American and British unit for car engines, motorcycles, motorboats, and traditional mechanical power ratings. James Watt invented the unit in the 1780s to market his steam engines: he calculated that a brewery horse could continuously turn a mill wheel at 33,000 ft·lb per minute, which became 1 horsepower. American cars typically range from 150 hp (economy) to 700 hp (sports cars), pickup trucks 250–500 hp, and large diesel trucks 400–600 hp. Outside the US, the metric horsepower (PS or CV, equal to 735.5 W — about 1.4% smaller than mechanical hp) is sometimes used. Horsepower relates to the watt (1 hp ≈ 745.7 W), the kilowatt (1 hp ≈ 0.746 kW), and the metric horsepower (1 hp ≈ 1.014 PS). Despite SI's preference for the watt, horsepower remains entrenched in automotive marketing.

  • US car and motorcycle engine ratings
  • Lawn mower and small engine specs
  • US pump and compressor ratings
Real-world examples

Base Ford Mustang: ~310 hp. Lawn mower: 5 hp. Average car: 150–200 hp.

What is the Metric Horsepower?

The Pferdestärke (PS), also called metric horsepower or 'cheval vapeur' (CV) in French, equals exactly 735.49875 watts — about 1.4% smaller than mechanical horsepower. Defined as the power needed to lift 75 kg by 1 meter in 1 second under standard gravity, the PS is the European traditional power unit for car engines. German, French, Italian, and Japanese car manufacturers historically rated engines in PS, and the unit persists in marketing — '300 PS' sounds slightly higher than '300 hp' to consumers. EU regulations require power to be specified primarily in kW, with PS allowed as a secondary unit. The PS relates to the watt (1 PS ≈ 735.5 W), the kilowatt (1 PS ≈ 0.7355 kW), and the mechanical horsepower (1 PS ≈ 0.9863 hp). The slight difference between PS and hp is mostly imperceptible in casual use but noticeable in precise engineering specifications.

  • European car and motorcycle ratings
  • Italian and German engine specs
  • Some European industrial equipment
Real-world examples

VW Golf GTI: ~245 PS = 180 kW. BMW M3: ~480 PS = 353 kW.

Learn About Both Units

Reference

What is the Mechanical Horsepower?

Read the unit page →
Reference

What is the Metric Horsepower?

Read the unit page →

Mechanical Horsepower to Metric Horsepower FAQ

5 questions
How many metric horsepower in a mechanical horsepower?
One mechanical horsepower equals 1.01387 metric horsepower.
How do I convert mechanical horsepower to metric horsepower?
Multiply the mechanical horsepower value by 1.01387 to get the equivalent in metric horsepower.
What is 100 mechanical horsepower in metric horsepower?
100 mechanical horsepower equals 101.38697 metric horsepower.
Is a mechanical horsepower bigger than a metric horsepower?
Yes. 1 mechanical horsepower equals 1.01387 metric horsepower, so one mechanical horsepower is larger.
How to convert mechanical horsepower to metric horsepower without a calculator?
Multiply by 1.01 for a quick estimate; use a calculator for precise results.

Related Power Conversions

Full comparison →

Conversions From Other Categories