This pipe sizer calculates the appropriate pipe size based on flow rate and maximum allowable velocity, with options for different pipe materials and fluids.

Hazen-Williams: Empirical formula commonly used for water in closed-loop systems. Uses a C-factor based on pipe material.

Darcy-Weisbach: Theoretical formula using friction factor calculated from Reynolds number. More accurate for non-water fluids.

Velocity Guidelines: Keep velocity between 4-8 ft/s for mains to balance erosion risk and sediment settling. Use 2-4 ft/s for branches.