Sewer pipe calculator

Sewer Pipe Calculations is a professional tool for engineers and technicians designing gravity sewer and drainage systems. Perform quick, accurate hydraulic calculations based on the Manning equation for partially full circular pipes.

Calculations included:
• Velocity & Depth — Find flow velocity and water depth given flow rate, slope, and diameter
• Diameter from Flow — Size the minimum pipe diameter for a design flow and slope
• Slope Range — Determine acceptable slope limits based on velocity and tractive force constraints
• Minimum Slope & Diameter — Simplified sewer design when only flow is known (ideal for condominial/small-bore systems)
• Flow & Velocity from Depth — Analyze existing pipes given geometry and water level

Key Features:
• Supports SI (metric) and US customary units
• Customizable pipe diameter catalog — add or remove standard sizes
• Built-in Theory section explaining all formulas and assumptions
• Bilingual interface: English and Spanish
• Clean, intuitive interface designed for field use

# Technical Foundation:
All calculations are based on the Manning equation for open channel flow, with proper treatment of partially full pipe geometry (central angle, wetted area, hydraulic radius). The app includes tractive force verification for self-cleansing design.

Perfect for civil engineers, sanitary engineers, and technicians working on sewer networks, drainage projects, and simplified sewerage systems.

Recent changes:
Calculating with the keyboard open now closes it, so the result is visible
straight away. One tap does both — before, the keyboard stayed over the number you had just calculated