How this calculator works
Calculate how much topsoil is needed to raise, fill or top-dress a rectangular area.
Formula
Volume = length × width × depth, converting inches to feet and cubic feet to cubic yards.
Volume = length × width × depth, converting inches to feet and cubic feet to cubic yards.
Example
A 20 × 10 ft area raised by 4 inches needs about 66.7 cubic feet, or 2.47 cubic yards.
Reliability check
Measure finished depth rather than excavation depth and decide whether the supplier quotes loose or compacted volume. Slopes, low spots and settlement can change the delivered quantity.
How to get a better estimate
- Loose soil can settle after placement.
- Irregular beds are easier to estimate by splitting them into rectangles.
- Confirm bag volume rather than bag weight.
What the result means
Loose and compacted soil volumes differ. Existing grade, settlement, moisture and the type of soil blend can change the delivered quantity required to reach the final elevation.
Reference tables
Use the mulch depth table as a pure geometric-volume check, then apply soil-specific settlement separately.