Mulch Calculator
Estimate cubic yards of mulch, whole bags, and purchase cost.
Estimate mulch
For one rectangular bed. Enter bag volume in cubic feet.
Mulch estimate
Whole bags to buy
- Bed area
- 200 ft²
- Volume
- 50 ft³
- Volume in cubic yards
- 1.85 yd³
- Whole-bag cost
- $112.50
A rectangular geometric estimate. Settling, irregular edges, existing material, and spillage are not included.
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Estimate mulch for a rectangular bed
Enter bed length and width in feet, desired mulch depth in inches, and the volume and price printed on a bag. The result provides total volume and whole bags to purchase.
Bag cost is based on rounded-up whole bags, not the proportional value of mulch used.
Formula
Area is length multiplied by width. Volume is that area multiplied by the depth in inches divided by twelve, which gives cubic feet; dividing by twenty-seven gives cubic yards. Bags are the volume divided by the volume per bag, rounded up.
Planning limitations
Real beds may have curved edges, slopes, existing mulch, plants, and uneven depth. Bag fill and material settling can also vary, so measure carefully and allow for some extra.
Bag volumes differ between products, commonly 1.5, 2, or 3 cubic feet, and larger quantities are often sold loose by the cubic yard instead. Check the figure printed on the bag you are buying, or confirm the yard price with the supplier, rather than relying on a remembered bag size.
Keep mulch pulled back from plant crowns and tree trunks rather than piling it against them.
Frequently asked questions
How is the mulch volume calculated?
Length times width gives area in square feet. Multiplying by depth converted from inches to feet gives cubic feet, which is divided by 27 for cubic yards.
Why does the calculator round the number of bags up?
Stores sell whole bags, so any partial-bag requirement is rounded upward to provide at least the calculated volume.
What mulch depth should I use?
Appropriate depth depends on the material, existing layer, plants, drainage, and project goals. Follow product and horticultural guidance for your site.
Does the estimate include settling or uneven ground?
No. The geometric estimate assumes a level rectangular area and the stated bag volume. Settling, compaction, irregular edges, and spillage can change actual needs.