Mulch & Soil Calculator — Bags vs Bulk
| Bed | Area (sq ft) | Cu ft | Cu yd |
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From "that bed over there" to a number the store understands
Mulch math fails at the units. You measure beds in feet, depth makes the volume three-dimensional, bags are labeled in cubic feet, bulk is sold by the cubic yard, and stone suppliers quote tons. This calculator walks the whole chain: add each bed (rectangles, circles, triangles, or straight square footage), set the depth, and it converts to cubic feet, cubic yards, bag counts and approximate tons using the density you enter. The plan is saved in your browser.
The math, in one pass
- Area: length × width for rectangles, π × (diameter ÷ 2)² for circles, base × height ÷ 2 for triangles. A 10×4 border is 40 sq ft.
- Volume: area × depth in inches ÷ 12. At 3 inches, that border needs 10 cubic feet.
- Yards and bags: divide cubic feet by 27 for cubic yards, or by the bag size for bags — 10 cu ft is 0.37 yd or five 2-cu-ft bags.
- Tons: cubic yards × the supplier-specific tons-per-yard value entered above.
Bags or bulk? Let the totals argue it out
A cubic yard equals 13.5 2-cu-ft bags, so the unit conversion is exact even though prices are not. Enter the actual bag price, bulk price and delivery fee and the calculator shows both totals and the difference. The bag-vs-bulk guide shows the same arithmetic.
Depth is the quiet multiplier
The same bed at 2 inches and 4 inches is a factor-of-two difference in everything downstream — volume, bags, dollars. Pick depth from the applicable plant, product or project guidance. Our mulch depth guide maps coverage per bag at each depth, and the raised-bed soil guide and patio-base gravel walkthrough cover the two jobs where depth math surprises people most. One scope note: this tool counts material — how a base should be built or compacted for your specific project is a construction question for local guidance, not a calculator.
Frequently asked questions
How many bags of mulch are in a cubic yard?
A cubic yard is 27 cubic feet, so it equals 13.5 of the common 2 cu ft bags. That one conversion is the key to every bag-vs-bulk price comparison — the calculator does it automatically.
How deep should mulch be?
This calculator does not prescribe depth. Enter the requirement from the product, plant guidance or project design. Doubling the entered depth doubles the calculated volume.
How do I measure a bed that isn’t a rectangle?
Use the circle or triangle shapes for round and corner beds, or measure an irregular bed roughly and enter its square footage directly with the custom shape. Splitting a curvy bed into two or three simple shapes gets you within a bag.
Is bulk delivery cheaper than bags?
The result depends on the prices and delivery fee you enter. The tool compares those exact inputs and makes no regional price or break-even claim.
What about gravel sold by the ton?
If a supplier quotes by weight, enter that supplier’s tons-per-cubic-yard conversion. Prefilled values are editable scenario defaults and are not suitable for ordering or engineering decisions without supplier confirmation.
Is my yard plan stored anywhere?
Only in your browser. Beds are saved on your device so the plan is still here next season; nothing is uploaded, and Clear removes it.
Related guides
How Much Mulch Do I Need? Depth, Bags per Yard, Tree Rings and Bags vs Bulk
University guidance on mulch depth (1–4 inches, kept off trunks), bag coverage by depth, 13.5 two-cubic-foot bags per yard, tree-ring math, top-ups and the bag-vs-bulk break-even.
How Much Soil for a Raised Bed: Depth by Crop, Mix and Bags (Plus Gravel for a Patio Base)
A 4x8 raised bed takes 21 cu ft of soil at 8 inches and 32 at 12. See extension guidance on depth by crop and compost share, bag counts, and the gravel-base volume-to-tons steps.