Free Construction Calculators & Tools/Drainage Pipe Calculator

Drainage Pipe Calculator

Size drainage pipes based on fixture units (DFU) and gradient requirements. Calculate branch, stack, and vent pipe diameters for residential and commercial plumbing systems.

Sanitary Fixtures

DFU = Drainage Fixture Units (measure of probable discharge)

Building & Pipe Details

Simultaneity factor: 0.5 (reduces peak load)

Calculate vertical stack for multi-floor buildings

Add fixtures and click Calculate to size drainage pipes

Notes:

  • Calculations based on BS EN 12056-2 for gravity drainage
  • DFU (Drainage Fixture Units) represent probable discharge
  • Simultaneity factors account for non-simultaneous usage
  • Stack sizing considers total load from all floors
  • Consult local codes for specific requirements
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DISCLAIMER

This calculator provides ESTIMATES for preliminary planning purposes. Results are based on standard assumptions and may not reflect your specific project conditions.

By using this tool, you acknowledge that:

1. All calculations are approximate and based on typical industry standards and assumptions.

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