Unit converter

Metric horsepower to mechanical horsepower.

Convert PS to hp and hp to PS. Type in either box and the other follows. PS is metric horsepower and is about 1.4% smaller than mechanical horsepower, so the same engine gets two different numbers.

PS → hpExact definition
Metric horsepower to mechanical horsepower — common values, to 6 significant figures.
PShp
50 PS49.316 hp
75 PS73.974 hp
100 PS98.632 hp
125 PS123.29 hp
150 PS147.948 hp
200 PS197.264 hp
250 PS246.58 hp
300 PS295.896 hp
400 PS394.528 hp
500 PS493.16 hp
1 PS=0.9863200706 hp 1 hp=1.013869665 PS

Definitions

  • Metric horsepower (PS, or cheval vapeur) is 735.498 75 W — about 1.4% smaller than mechanical horsepower, which is why the same car has two figures.
  • Mechanical horsepower is 745.6999 W, defined as 550 foot-pounds per second. It is the horsepower UK and US brochures quote.
  • This conversion is exact by definition. 1 PS = 0.9863200706 hp.
  • Power is converted through W.

How it works

One direction multiplies and the other divides by the same number, so nothing is lost by going back and forth.

The value passes through W, the unit every other power unit on the site is defined against, rather than a number written into this page on its own. That is why the figure here, the figure in the table above and the general power converter always agree.

Display precision limits significant figures rather than decimal places, because one fixed number of decimals is useless across a range this wide. Very large and very small results switch to scientific notation with a proper superscript exponent. The editable box always holds a plain number at full working precision, so you can carry on from either side.

Common questions this answers: how many mechanical horsepower in a metric horsepower (ps) (0.98632), how many metric horsepower in a horsepower (mechanical) (1.01387), and what 150 PS is in mechanical horsepower (147.948 hp).