Calculator
Mulch Calculator
Enter your bed size and desired depth to get bags and cubic yards.
Model reviewed August 2026
Mulch needed
63 bags
2 cubic foot bags
- Cubic yards
- 4.63
- Cubic feet
- 125
- Cost estimateBagged; bulk delivery is usually cheaper over 3 cubic yards
- $252 – $441
Estimates only. Local pricing, site conditions and code requirements change the real number.
The formula
Cubic yards = (area x depth in feet) / 27; Bags = cubic feet / 2
Standard mulch bags hold 2 cubic feet. Thirteen and a half bags equal one cubic yard.
Worked example
A 500 sq ft bed at 3 inches deep needs 125 cubic feet — about 63 bags or 4.6 cubic yards.
Frequently asked questions
How many bags of mulch in a yard?
13.5 bags of 2 cubic foot mulch make one cubic yard. Above about three yards, bulk delivery is almost always cheaper.
How deep should mulch be?
Three inches is the sweet spot. Deeper than four inches can suffocate roots and hold too much moisture against stems.
Sources
Sources & verification
- International Residential Code — decks and exterior structures (R507)
- ICPI segmental paving installation guidance
- International Code Council (IRC/IBC)
Model vintage August 2026. The links above are the issuing agencies' own pages — we publish them so you can confirm the current rule yourself, not as evidence that each fact on this page was re-checked with them today. Cost figures are modeled estimates based on national baselines adjusted for local labor and material pricing, not quotes. Permit rules change; confirm with the building department before starting work.