# Water Pipe Sizing

Written by Jerry Ratzlaff on . Posted in Fluid Dynamics

## Water Pipe Sizing formula

 $$\large{ d = \frac{1}{12} \sqrt { \frac { 0.134 \; Q_w } { 3600 } \; \frac { 4 } { \pi } } }$$

### Where:

 Units English Metric $$\large{ d }$$ = pipe inside diameter $$\large{in}$$ $$\large{mm}$$ $$\large{ \pi }$$ = Pi $$\large{3.141 592 653 ...}$$ $$\large{ Q_w }$$ = water flow rate $$\large{\frac{ft^3}{sec}}$$ $$\large{\frac{m^3}{s}}$$