PipeKit — Plumbing Engineering Calculators

Fast, reliable plumbing engineering calculations: size pipes, check pressure loss and velocity, size drains, vents, storm drainage, water heaters, expansion tanks, and convert units — under IPC & CPC (US customary units, SI where noted).

This app requires JavaScript. Results are engineering estimates — always verify against the adopted code and applicable local amendments.

Calculators

Pipe sizing & velocity
Pressure drop (Hazen–Williams)
Water supply demand (WSFU)
Drainage load (DFU)
Drain / sewer sizing by slope
Vent sizing (simplified)
Storm drainage leaders
Water heater recovery
Thermal expansion tank
Unit converter

Reference

IPC 2024 and California Plumbing Code 2022 fixture units, drainage capacities, vent rules, storm tables, and supply demand curves.