The Manning formula, also referred to as the Gauckler–Manning formula, or Gauckler–Manning–Strickler formula, is a formula for open channel flow, or free-surface flow driven by gravity.
Use this effective app to help determine the calculations required.
With over 18 pre-defined Gauckler–Manning coefficients to make your life easier. If one isn't there, simply enter the coefficient in the relevant area.
Please note this app is in imperial measurements.