Compare calculators
Both calculators run independently β change the inputs on either side to compare results.
Civil
Storm Water Runoff Calculator
Estimate peak stormwater runoff flow from a drainage basin using the Rational Method. Ideal for sizing storm drains, culverts, and detention ponds for small urban and suburban catchments under 200 acres.
Fill in the required fields to see your result.
Civil
Pipe Flow Capacity Calculator
Determine water flow rate (in GPM) through circular pipes using Manning's equation. Used by civil engineers and plumbers to size pipes for gravity-fed drainage, sewer, and stormwater systems.
Fill in the required fields to see your result.
Key differences
| Storm Water Runoff Calculator | Pipe Flow Capacity Calculator | |
|---|---|---|
| Category | Civil | Civil |
| Inputs required | 3 | 4 |
| Result | Peak Runoff Flow (cfs) | Flow Capacity (gallons per minute) |
| What it does | Estimate peak stormwater runoff flow from a drainage basin using the Rational Method. Ideal for sizing storm drains, culverts, and detention ponds for small urban and suburban catchments under 200 acres. | Determine water flow rate (in GPM) through circular pipes using Manning's equation. Used by civil engineers and plumbers to size pipes for gravity-fed drainage, sewer, and stormwater systems. |