Slope & Fall Calculator
Calculate drain slope, total fall, or run length.
Slope Requirements
| Pipe Size | Min Slope | % Grade |
|---|---|---|
| 2-1/2" and smaller | 1/4" per foot | 2.08% |
| 3" to 6" | 1/8" per foot* | 1.04% |
| 8" and larger | 1/16" per foot* | 0.52% |
*1/4" per foot required unless otherwise approved. Check local code.
Slope Conversions
- 1/8" per foot = 1.04% = 1:96
- 1/4" per foot = 2.08% = 1:48
- 1/2" per foot = 4.17% = 1:24
- 1" per foot = 8.33% = 1:12