Plumbing DWV Pipe Sizing Calculator
Code Version
Building Type
Drain Slope
Fixtures
Total DFU14
Building Drain Size2"
Fixture DFU Tally
| Fixture | Count↕ | DFU Each↕ | Total DFU↕ |
|---|---|---|---|
| Toilet | 2 | 4 | 8 |
| Lavatory | 2 | 1 | 2 |
| Shower | 1 | 2 | 2 |
| Kitchen Sink | 1 | 2 | 2 |
Pipe Sizing
| Component | Size↕ | Notes↕ |
|---|---|---|
| Building Drain | 2" | 14 DFU total, 1/4" per ft slope |
| Branch — Toilet | 2.5" | 8 DFU |
| Branch — Lavatory | 1.5" | 2 DFU |
| Branch — Shower | 1.5" | 2 DFU |
| Branch — Kitchen Sink | 1.5" | 2 DFU |
| Vent Stack | 2" | 14 DFU connected |
Trap Arm Distances
| Fixture | Trap Size↕ | Max Trap Arm Distance↕ |
|---|---|---|
| Toilet | 3" | 6 ft |
| Lavatory | 1.25" | 5 ft |
| Shower | 2" | 8 ft |
| Kitchen Sink | 1.5" | 6 ft |