Manning's Equation Calculator - Engineering Calculator Box

Q = (1/n) × A × R^2/3 × S^1/2
where: Q = flow rate, n = Manning's roughness, A = cross-sectional area, R = hydraulic radius, S = slope

Channel Type

Channel Slope (m/m or ft/ft) Example: 0.001 for 0.1% slope

Manning's Roughness Coefficient (n) Typical values: concrete (0.012), PVC (0.009), earth (0.025)

Unit System

Enter channel parameters to calculate flow characteristics.