Sewer Pipes - Capacities vs. Slope
Carrying capacities of sewer and wastewater pipes - gpm and liter per second. Calculate pipe capacity based on diameter and slope, and convert between decline and slope units.
Sewer Pipe Capacity Calculator
Calculate the capacity of sewer and wastewater pipes based on diameter and slope. These calculations are based on clean plastic pipes using the Manning formula with roughness coefficient 0.015 and 50% fill.
Decline and Slope Conversion
Convert between decline (%) and slope units using the following relationships:
- d = 8.33 × s(in/ft)
- d = 100 × s(ft/ft)
- d = 100 × s(m/m)
- d = s(ft/100ft)
Where d = decline (%) and s = slope
Reference Data
Conversions
- 1 gal (US)/min = 6.30888×10⁻⁵ m³/s
- 1 gal (US)/min = 0.227 m³/h
- 1 gal (US)/min = 0.06309 dm³(liter)/s
- 1 gal (US)/min = 2.228×10⁻³ ft³/s
- 1 gal (US)/min = 0.1337 ft³/min
- 1 gal (US)/min = 0.8327 Imperial gal (UK)/min
Example
The capacity of a 4 inch sewer pipe with decline 0.5% is approximately 25 gpm (1.6 liter/s).