Site Grading and Drainage Slope Calculator

Determine actual slope, verify drainage minimums, and get grading recommendations.

Elevation at the high point of the grading area.
ft
Elevation at the low point or drainage outlet.
ft
Horizontal distance between the high and low points.
ft
Minimum slope percentage required by code or design. Typical: 1-2% for surface drainage.
%
Soil type affects drainage and infiltration rates. Clay drains poorly; sand drains well.

Results

Actual Slope-%
Meets Minimum-
Fall per 10 ft-in
Swale Depth Recommendation-in
Drain Spacing-ft
Reference: Based on general civil engineering drainage guidelines. Local codes and soil reports should be consulted for final design.