What’s the speed of the water coming out the nozzle of my pressure washer? [FAQ011]

Today we will look at the speed of the water coming out of the pressure washer nozzle.

A pressure washer with a flow rate of 3 GPM using a typical 0-degree nozzle with an orifice size of 0.052″ (1.32mm) has a water speed out the nozzle of 243 mph (391 km/hr).

Speed of pressure washer water graphic


  • 3 gallons per minute pressure washer flow rate is 11.3562 litres/minute is 189.25 cm3/second
  • Orifice size is 0.132 cm
  • Divide the flow rate by the orifice size squared to get units of cm/sec
  • Convert cm/sec to miles per hour and kilometres per hour.