# Water and Wastewater Terms Beginning M

A B C D E F G H I J K L M N O P Q R S T U V W Y Z

# Manning's Formula

A mathematical formula for calculating wastewater flows in sewers.

- Q means flow in cubic feet per second (CFS) (cubic meters per second (m
^{3}/s)). - n means the Manning pipe or channel roughness factor.
- A means the cross-sectional area of the flow in square feet (sq ft) (square meters (m
^{2})). - R means the hydraulic radius in feet (meters) where R equals A/P. P is the wetted perimeter of the channel or pipe in feet (meters).
- S means the slope of the channel or energy grade line in feet per foot (ft/ft) (meters per meter (m/m)).