Calculate sewer pipe slope, drain line pitch, total fall, percent grade, elevation drop, and pipe run. Use this calculator for sewer lines, building drains, horizontal drains, waste lines, and gravity drainage planning.
Total fall from slope:
The calculator multiplies pipe run by slope to estimate the total elevation drop needed.
Slope from fall:
The calculator divides total fall by pipe run to estimate inches per foot, percent grade, and degrees.
Pipe run from fall:
The calculator divides available fall by target slope to estimate the maximum pipe run.
Elevation check:
The calculator compares start elevation and end elevation to calculate actual fall and slope.
A sewer pipe slope calculator helps estimate the fall needed for gravity drainage, sewer lines, building drains, horizontal waste lines, and underground drain runs.
It can help compare inches per foot, percent grade, degrees, total fall, pipe run, elevation drop, and target slope.
Your result shows estimated sewer pipe slope, total fall, grade, and pipe run. Sewer and drain systems are code-sensitive, and actual slope requirements depend on pipe size, fixture load, local plumbing code, venting, fittings, cleanouts, and site conditions.
Sewer pipe slope is the amount a pipe drops over its run. It is commonly shown as inches of fall per foot of pipe.
It means the pipe drops 1/4 inch for every 1 foot of horizontal run. Over 50 feet, that equals 12.5 inches of total fall.
Multiply the pipe run by the slope. For example, 50 feet at 1/4 inch per foot equals 12.5 inches of fall.
No. This calculator gives a planning estimate. Final sewer pipe slope should follow local plumbing code and be verified for the actual pipe size, layout, and site conditions.