How much mulch or landscape rock do I need?
Measure beds and paths by area, choose a depth, and compare bulk, bag, or weight-based material quantities.
Short answer
Measure the area, subtract uncovered sections, multiply by the depth you want, and use the product's bag volume or density for the buying unit.
For homeowners comparing bagged or delivered mulch, gravel, or decorative landscape rock.
How to do it
Measure the sections
Add each bed, path, or strip that will receive the same material and depth.
Remove spaces you will not cover
Use exclusions for paths, edging, plants, or other uncovered areas when needed.
Enter depth and product details
Set depth first, then add bag volume, density, or price from the supplier.
Compare the buying unit
Review volume, whole bags, or estimated tons and ask the supplier how the material is delivered.
Formula
Net area multiplied by depth gives volume. Convert that volume to bags or multiply cubic yards by the entered density for estimated tons.
Illustrative example
A 500 sq ft bed at 3 inches needs 125 cu ft, or about 4.63 yd³. With 2 cu ft bags, that rounds to 63 bags.
Common mistakes
- Using one depth for areas that need different depths
- Treating density as a universal material fact
- Ignoring delivery access and staging
Before you buy
Confirm bag fill, bulk unit, density, delivery placement, and whether the supplier's weight is loose or delivered.
What this guide does not cover
The tools do not design grading, drainage, edging, fabric, base preparation, or the maintenance depth for a particular landscape.
Use the calculator
Mulch Calculator is the primary tool for this guide. You can also browse the other landscaping calculators.