Drainage Slope Calculator | Free Construction Calculators

Calculate minimum required slope for drainage pipes based on diameter and type.

About Drainage Slopes

Proper drainage slope is critical for self-cleaning flow and preventing clogs. Building codes specify minimum slopes based on pipe diameter and the type of waste being carried. These calculations follow IPC (International Plumbing Code) standards.

Typical Minimum Slopes

  • • 2-3 inch sanitary: 1/4 inch per foot
  • • 4 inch and larger: 1/8 inch per foot
  • • Storm drains: Can be less steep
  • • Always verify with local codes