Mulch Calculator

How to use this calculator

Enter Length (ft), Width (ft), Depth (in). The result updates in your browser as you edit an input. The prefilled values are examples only.

How the estimate works

Multiply length and width by depth converted to feet, then divide cubic feet by 27.

What can change the answer?

Actual bed shape and settled depth may differ from a simple rectangle. Measure several spots when the ground slopes or the depth changes.

Before relying on the result

Use feet for length and width, and inches for intended layer depth. Split curved or uneven beds into sections, add their volumes, and keep any purchase allowance separate. Convert the result to bags using the stated bag volume; material weight cannot be inferred from volume alone.

Further reference

Iowa State University Extension: determining mulch quantity explains area, depth, cubic-foot volume, bag counts and conversion to cubic yards. Use the depth appropriate to your material and situation; this calculator does not choose it.

Worked example with the default inputs

A 20-by-8-foot bed at 3 inches deep contains 40 cubic feet, or 1.48 cubic yards. With bags marked 2 cubic feet, that geometric volume corresponds to 20 bags before any explicit allowance.

Interpret the result in a planning record

The mulch calculator combines bed length, width and depth. It reports volume rather than weight because moisture and material type can change weight. If the bed has curves, divide it into manageable sections. When converting the result to bags, use each bag’s stated cubic-foot volume and round the purchase count to whole bags.

Save the input values, units and result together. Change one uncertain input at a time so you can see which assumption moves the answer. A displayed decimal is arithmetic precision, rather than evidence that the measurements or rates are equally precise.

More tools

Read the How to Measure a Lawn and Read Product Rates guide →