Storm Drain Pipe Sizer

Rational Method & Manning Eq

$1.99 · Designed for iPad. Not verified for macOS.

Storm drain pipe sizing with Rational Method. Need to size a storm drain pipe but tired of flipping through design manuals? This calculator does the hydraulics for you in seconds. Enter rainfall intensity, drainage area, runoff coefficient, pipe slope, and material to get the exact pipe diameter your project needs. No more guessing between standard sizes. WHAT YOU GET: - Peak runoff flow (Q) via the Rational Method - Required pipe diameter from Manning equation - Nearest standard pipe size recommendation - Full-pipe flow velocity and capacity check - Self-cleansing velocity verification SURFACE TYPES: Rooftop, concrete, gravel, flat lawn, steep lawn, and forest — each with standard runoff coefficients built in. PIPE MATERIALS: Concrete, PVC, corrugated metal, and HDPE with accurate Manning roughness values. STANDARD SIZES: Recommends from 4-inch through 60-inch standard pipe diameters. Works completely offline. No account required. Built for civil engineers, stormwater designers, and site contractors who need fast, reliable pipe sizing on the job.

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Bug fixes and performance improvements.

Version 1.0.2

The developer, Shanghai Sheyuan Network Technology Co., Ltd., indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

  • Data Not Collected

    The developer does not collect any data from this app.

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    Accessibility

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    Information

    Seller
    • Shanghai Sheyuan Network Technology Co., Ltd.
    Size
    • 953.3 KB
    Category
    • Utilities
    Compatibility
    Requires iOS 17.0 or later.
    • iPhone
      Requires iOS 17.0 or later.
    • iPad
      Requires iPadOS 17.0 or later.
    • Mac
      Requires macOS 14.0 or later and a Mac with Apple M1 chip or later.
    • Apple Vision
      Requires visionOS 1.0 or later.
    Languages
    • English
    Age Rating
    4+
    Copyright
    • © 2026 Sheyuan Inc.
  • Developer Website
  • Privacy Policy

    • Supports

    • Family Sharing

      Up to six family members can use this app with Family Sharing enabled.

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