Free estimate — verify against local code before building
Mulch Calculator
Convert bed area and depth to yards and bags of mulch, then see whether bags or a bulk delivery is cheaper at your prices.
What this calculator includes
Enter the bed area or measure the main bed and add the rest, then pick a depth — 3 inches is the standard for weed suppression, and a 2 inch coat handles most annual refreshes. The calculator converts the bed to cubic feet, yards, and 2 cu ft bags, then prices both ways to buy: bags at your store price against bulk delivery rounded to the supplier's half-yard increment plus the delivery fee. New-bed mode also adds landscape fabric, staples, and edging to the shopping list. Every price is an editable assumption.
How to use this mulch calculator
- 01
Measure the beds
Enter the combined bed area, or measure the main bed's length and width and put the rest of the beds in the additional-area field. Split odd shapes into rectangles and add them up.
- 02
Pick depth and project mode
Use 3 inches for a new bed that has to suppress weeds and 2 inches to top up existing mulch. New-bed mode also plans fabric, staples, and edging; refresh mode is mulch only.
- 03
Enter both prices
Put in the store's 2 cu ft bag price plus the local supplier's per-yard bulk price and delivery fee. The calculator totals both and names the cheaper option with the dollar difference.
- 04
Order the winner
Buy bags for small beds and easy hauling, or schedule the bulk delivery when it wins. Confirm the supplier's minimum order and delivery increment before you commit.
Calculation sources and review
Primary references and formula assumptions are linked so you can verify them against the selected product, supplier, and adopted local requirements.
Internal formula review completed July 13, 2026. What this review covers
- Clemson Cooperative Extension HGIC — Mulch (opens in a new tab)
Recommended 2–3 inch application depths and mulching practice.
- Mulch & Soil Council (opens in a new tab)
Industry product-certification body for bagged mulch and soil.
- Lowe's — mulch buying guide (opens in a new tab)
Retail bag sizes and coverage guidance; the bag label controls.
Frequently asked questions
How many bags of mulch are in a cubic yard?
13.5 bags at the common 2 cu ft size, since a cubic yard is 27 cubic feet. That means 63 bags for a 500 sq ft bed at 3 inches deep — the point where a bulk delivery usually starts to make sense.
How deep should mulch be?
3 inches is the standard depth for suppressing weeds in a new bed; a 2 inch coat is enough for an annual refresh over existing mulch. Stay under 4 inches and keep mulch pulled back from trunks and stems.
Is bulk mulch cheaper than bagged mulch?
Usually only above a few cubic yards. Bags carry no delivery fee, so small beds favor bags; bulk wins once the per-yard saving covers the delivery charge. At $4 bags and $45/yd³ bulk with $75 delivery, the break-even is around 8 cubic yards.
How much does one cubic yard of mulch cover?
108 sq ft at 3 inches deep, 162 sq ft at 2 inches, and 81 sq ft at 4 inches, before any waste. Divide 324 by the depth in inches to get coverage per cubic yard.
Do I need landscape fabric under mulch?
Only in new beds where you want extra weed blocking under stone or long-lived plantings — many gardeners skip it in beds that get replanted, since fabric complicates future digging. If you use it, overlap seams and pin it with staples before spreading mulch.