Unit Conversion

Convert numbers between two units quickly and precisely

Power Converter

Unit Conversion

Convert power units: watt, kilowatt, PS, and horsepower

Power, defined as energy per time, is stated in watt (W), the SI unit, as well as kilowatt (kW) and megawatt (MW) for larger amounts. For vehicle engines, PS (metric horsepower) and hp (mechanical horsepower, common in the US/UK) are used – similar in size but not identical. In heating and cooling engineering, power is sometimes stated in BTU per hour.

Key conversion factors:

  • 1 kilowatt (kW) = 1,000 watt (W)
  • 1 PS (metric horsepower) = 735.5 watt – metric definition, common in Europe
  • 1 horsepower (hp) = 745.7 watt – mechanical definition, common in the US and UK
  • 1 PS ≈ 0.9863 hp – the two units differ by just under 1.4%
  • 1 BTU per hour (BTU/h) = 0.293 watt – common for air conditioner power ratings

Applications:

  • Automotive engineering: comparing engine power between PS and kW, e.g. for US vehicle specs
  • Electrical engineering: power ratings of devices and systems in watt and kilowatt
  • Heating & cooling engineering: converting heating or cooling capacity between watt and BTU/h

The power converter delivers exact values for vehicle comparisons and technical calculations. For energy (power times time), use the energy converter; for torque, the torque converter.

Frequently asked questions about converting power

1 PS (metric horsepower) equals 0.7355 kilowatt (kW). Conversely, 1 kW equals about 1.36 PS. This metric definition of PS is common in Europe.

PS (metric horsepower, 735.5 W) and hp (mechanical horsepower, 745.7 W) are two differently defined units that historically both aimed to represent "one horse". The difference is just under 1.4% – US vehicle data usually means hp, while Europe uses PS.

1 watt equals 3.412 BTU per hour (BTU/h), and 1 BTU/h equals 0.293 watt. This conversion is often needed for air conditioner power ratings, which are frequently given in BTU/h.