Formula
Width and depth stay in inches:
cubic yards = length × width × depth / 3888
The divisor converts both inch measurements to feet and then cubic feet to cubic yards. A turned-down edge or a pier is not added.
Assumptions
- The footing is a straight rectangular strip.
- Length is feet. Width and depth are inches.
- One cross-section runs the whole length.
Worked example
A 40 foot footing, 16 inches wide and 8 inches deep, is 1.32 yd³.
Input definitions
- Width
- The horizontal cross-section, in inches.
- Depth
- The vertical cross-section, in inches.
Limitations
This is a planning quantity. It is not a structural design, a permit drawing, or a supplier's guaranteed yield.
Questions
How is this different from the slab page?
The slab page takes two foot dimensions and one inch thickness. This page takes one foot length and two inch cross-section dimensions.
Does it include the wall above the footing?
No. Only the strip described by length, width, and depth.