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Both calculators run independently — change the inputs on either side to compare results.
Fluid Mechanics
Manning's Roughness Flow Calculator
Estimate average flow velocity in an open channel or partially-full pipe using Manning's equation with hydraulic radius, slope, and roughness coefficient. Useful for stormwater design, culvert sizing, channel design, and natural-stream hydraulic analysis.
Fill in the required fields to see your result.
Fluid Mechanics
Manning's Equation Open Channel Calculator
Compute flow velocity and discharge in open channels — rivers, canals, and drains — using Manning's equation. Essential for flood modelling, irrigation design, and stormwater drainage sizing.
Fill in the required fields to see your result.
Key differences
| Manning's Roughness Flow Calculator | Manning's Equation Open Channel Calculator | |
|---|---|---|
| Category | Fluid Mechanics | Fluid Mechanics |
| Inputs required | 3 | 4 |
| Result | Flow Velocity (m/s) | Flow Rate (m³/s) |
| What it does | Estimate average flow velocity in an open channel or partially-full pipe using Manning's equation with hydraulic radius, slope, and roughness coefficient. Useful for stormwater design, culvert sizing, channel design, and natural-stream hydraulic analysis. | Compute flow velocity and discharge in open channels — rivers, canals, and drains — using Manning's equation. Essential for flood modelling, irrigation design, and stormwater drainage sizing. |