Sanitary Drainage Calculator
The Sanitary Drainage Calculator sizes the sanitary stack from the total drainage fixture units and design flow. Example: for a 3-floor building sanitary stack serving 10 water closets, Total DFU = 40 DFU, Stack size = 100 mm, Design flow = 5.42 L/s (per NSCP Vol.2 | PSME Code | ASPE Vol.2 | IPC (as adopted by NSCP)).
How it works
Computed from your inputs per NSCP Vol.2 | PSME Code | ASPE Vol.2 | IPC (as adopted by NSCP).
Worked example (Plumbing & Pumps)
Inputs: a 3-floor building sanitary stack serving 10 water closets.
| Result | Value |
|---|---|
| Total DFU | 40 DFU |
| Stack size | 100 mm |
| Design flow | 5.42 L/s |
Computed live by WorkHive's calculation engine; standard: NSCP Vol.2 | PSME Code | ASPE Vol.2 | IPC (as adopted by NSCP).
How to use this calculator
- Enter the figures for the duty you are sizing: the worked example below uses a 3-floor building sanitary stack serving 10 water closets.
- The calculator returns Total DFU, Stack size, Design flow, computed per NSCP | Philippine Plumbing Code.
- Check the worked example to confirm the method matches how you would do it by hand, then run your own numbers in the interactive tool.
FAQ
What is a sanitary sewer sizing calculator DFU?
The Sanitary Drainage Calculator is a free online tool that computes sizes the sanitary stack from the total drainage fixture units and design flow. It shows the formula and a fully worked example so you can check the method, not just the number.
How is it calculated?
The result is computed from your inputs following NSCP | Philippine Plumbing Code. The worked example on this page shows a real computation with real numbers.
Is the calculator free?
Yes. WorkHive's engineering calculators are free to use, no sign-up needed for the tools. WorkHive is a free, offline-first maintenance platform built for Philippine industrial plants.
Run it on your own numbers
Open the interactive Sanitary Drainage Calculator in WorkHive: free, no sign-up needed for the calculators.