Power conversion - hp,kw,ps...

The following utility will enable you to convert power expressed in one unit to another unit

For very small numbers or to improve rounding you can use this to control the number of decimal places displayed
Convert
to
Power is generally expressed in watts (W). The information in the table below provides a method of converting power from other units to watts.
Convert from these to watts (W)multiply by
erg's per second (erg/s)0.000 000 1
horsepower (electric)746
horsepower (hp)(metric,DIN,PS)735.4988
horsepower (hp)(U.K.)745.7
kilowatt (kW)1000

Examples:

How do I convert PS to horsepower?

A manufacturer quotes the power of a vehicle at 250PS (Pferdestärke - German for horsepower, equal to metric horsepower and sometimes referred to as 'continental horsepower') converted to watts this would be 183874.7 (250 x 735.4988) and converted to horsepower (imperial) it would be 246.58 (183874.7 / 745.7).

To avoid all that hassle you could go straight from 250PS to 246.58hp just by dividing 250 by 1.01387 or by using the calculator above

Which is bigger, Horsepower DIN or Horsepower PS?

They are exactly the same, also known as metric horsepower.

Why are cars rated as 280hp in Japan but 276hp in the U.K.?

They use Metric horsepower(DIN/PS) as above, converted to imperial/UK/mechanical horsepower it's 276.17 which gets rounded to 276hp.