Pressure Washer Hose Friction Loss

Most pressure washers work best with 3/8" ID hose.

As you can see from the chart. Pressure will drop over the length of a hose from friction. The pressure drop across a given hose length is directly proportional. A 50 foot hose will lose exactly 1/2 the pressure of a 100ft hose. The chart values are valid at all pressure levels.

General rule for hose ID.

  • 1/4" ID - 0 to 3.0 gpm
  • 3/8" ID - 3.0 to 8.0 gpm
  • 1/2" ID - 8.0 gpm to 15gpm