Compare calculators
Both calculators run independently β change the inputs on either side to compare results.
Civil
Culvert Flow Calculator
Calculate the full-flow discharge capacity of a circular culvert using Manning's equation. Used by drainage engineers to check whether an existing or proposed culvert can pass a design flood without overtopping.
Fill in the required fields to see your result.
Civil
Culvert Design Calculator
Size a circular or box culvert to pass a design stormwater discharge using Manning's equation. Essential for highway engineers, drainage designers, and land developers ensuring roads stay clear during storm events.
Fill in the required fields to see your result.
Key differences
| Culvert Flow Calculator | Culvert Design Calculator | |
|---|---|---|
| Category | Civil | Civil |
| Inputs required | 4 | 5 |
| Result | Flow Rate (cfs) | Required Culvert Diameter (m) |
| What it does | Calculate the full-flow discharge capacity of a circular culvert using Manning's equation. Used by drainage engineers to check whether an existing or proposed culvert can pass a design flood without overtopping. | Size a circular or box culvert to pass a design stormwater discharge using Manning's equation. Essential for highway engineers, drainage designers, and land developers ensuring roads stay clear during storm events. |