Pipe Sizing Calculator

Find the smallest pipe size that satisfies your velocity or pressure-drop limits. Enter flow rate, fluid properties (or pick from the library), and either a maximum velocity or a maximum allowable pressure drop per length. The calculator iterates through standard pipe schedules (Sch 40, Sch 80, custom) and returns the smallest commercial size that passes.

Velocity-limited sizing is common for liquid lines (typically 1–3 m/s for water service). Pressure-drop-limited sizing dominates compressible gas distribution where total ΔP across a long run matters more than instantaneous velocity. Both use Darcy-Weisbach with Colebrook-White friction.

Related: friction loss, Reynolds number, pipe schedule reference. For multi-pipe networks, build a model in SimuPipe.