Trench Slope Calculator (OSHA 1926 Subpart P)

Bottom width

Trench Depth

OSHA trench slope requirements

According to OSHA excavation standards (29 CFR 1926 Subpart P), trenches deeper than 5 feet must use a protective system unless the excavation is made entirely in stable rock. One common method of protection is sloping the trench walls based on soil classification.

Soil Types

How to use the calculator?

Type A soil — ¾:1 slope
Type B soil — 1:1 slope
Type C soil — 1.5:1 slope

Enter bottom width
Enter the depth
Select soil type