Flow Rate Pipe Calculator Pro

FLOW is an offline pipe flow rate calculator for water in round, full pipes. Size a run from inner diameter, length, and material — or invert a frictional pressure drop to estimate flow. There is no live hardware and no system-online dashboard.

What you can calculate

• Continuity: Q = A·v (flow from velocity or velocity from flow)
• Darcy–Weisbach head loss with a Churchill friction-factor approximation and a commercial roughness table
• Hazen–Williams (water) as a comparison method
• Reynolds number and laminar / transitional / turbulent band
• Velocity warnings when the mean speed is low, high, or excessive
• Unit toggles: L/min, m³/h, GPM · mm/inch · bar/psi/kPa · m/ft

Save named scenarios on the device and share a text summary (FLOW Pro). Charts are educational plots of the current inputs — not 24-hour telemetry.

FLOW Pro (soft yearly unlock, pro.yearly)

• Unlimited saved scenarios (free tier keeps 3)
• Custom roughness ε and Hazen–Williams C
• Extra materials and Darcy vs Hazen comparison
• Share/export and educational charts

Educational disclaimer

Results are estimates for straight circular water pipes. They omit fittings, elevation, pumps, and code tables. FLOW is not a licensed plumbing or engineering stamp.

Subtitle: Pipe GPM Plumbing
In-app brand: FLOW
Category: Tools

Recent changes:
1.0.1 — Offline pipe flow (Darcy–Weisbach / Hazen–Williams). Pro via Play Billing (pro.yearly).