
Garden Hose Flow and Time Calculator
The assumed C factor (internal to the equation constant) is 135 for flexible garden hoses. Water Flow Rate. Where: = Water flow rate from the end of the hose (gpm) = Pressure at the hose bib while hose end is free flowing (dynamic pressure, not static pressure) (psi) = Hose internal diameter (in) = The hose length (ft) Water Flow Time. Where: