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Both calculators run independently — change the inputs on either side to compare results.
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.
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.
Key differences
| Manning's Equation Open Channel Calculator | Manning's Roughness Flow Calculator | |
|---|---|---|
| Category | Fluid Mechanics | Fluid Mechanics |
| Inputs required | 4 | 3 |
| Result | Flow Rate (m³/s) | Flow Velocity (m/s) |
| What it does | 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. | 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. |