inch per foot
Slopeexact by definition
One inch of fall per foot of run, equal to a ratio of one twelfth or about 8.33 percent. It is the working unit of North American plumbing, where the classic minimum drainage fall is a quarter inch per foot.
| 1 | 0.083333333 |
Where the unit came from
The quarter-inch-per-foot rule — a 1:48 slope — comes from a genuine physical window rather than tradition. Too flat and the liquid does not carry the solids; too steep and the liquid outruns them, leaving solids stranded in the pipe. Both failures block a drain, which is why plumbing codes give a minimum and a maximum rather than a floor alone.
One inch per foot in every slope unit
| 0.0833333 | meter per meter (m/m) | |
| 8.33333 | percent grade (%) | |
| 83.3333 | millimeter per meter (mm/m) | |
| 83.3333 | per mille (‰) | |
| 0.0833333 | foot per foot (ft/ft) | |
| 1 | inch per foot (in/ft)this unit |
Solvers that use slope