# Hazen-Williams Flow Rate Equation

Written by Jerry Ratzlaff on . Posted in Fluid Dynamics

This flow rate formula is used in Hazen-Williams equations and the coefficient formula.  This formula only works for ambient temperatute and turbulent flow.

## Formulas that use Hazen-Williams flow Rate Equation

 $$\large{ Q = 0.285 \; C\; d^{2.63} \; m^{0.54} }$$

### Where:

$$\large{ Q }$$ = flow rate

$$\large{ C }$$ = Hazen-Williams Coefficient

$$\large{ m }$$ = hydraulic grade line slope

$$\large{ d }$$ = inside diameter of pipe