Manning’s Equation Calculator February 28, 2019 Author: webadmin This is a simple script that computes normal flow for pipes and rectangular channels. I wrote this on JavaScript at some point when I needed to determine flow capacities for pipes. Shape: Circular Rectangular Diameter, d (ft) Roughness, n Slope, s Depth, y (ft) Units English Metric Area, A (ft2) Perimeter, P (ft) Radius, R (ft) Velocity, V (fps) Flow, Q (cfs) Categories: STEM Tags: manning, normal flow, script