Mulch Calculator
Yards or bags for every bed — added up in one list.
Your beds
Materials list
Generated by AllUnits.io — allunits.io/calculators/mulch
How this calculator figures it
One cubic yard covers 324 square feet at a 1-inch depth — the industry "324 rule" — so yards needed are square feet × depth in inches ÷ 324. A 2–3 inch layer is the standard recommendation for weed suppression and moisture retention; 13.5 two-cubic-foot bags equal one yard.
How it works
Worked example — a 20 × 5 ft bed at 3 inches: 100 sq ft × 3 ÷ 324 = 0.93 yd³ of bulk mulch, or 13 two-cubic-foot bags. Coverage per yard: 324 sq ft at 1", 162 at 2", 108 at 3".
Mulch FAQs
How deep should mulch be?
2–3 inches; landscape pros recommend 3. Keep it off trunks and stems.
How many bags in a yard?
13.5 two-cu-ft bags.
How much does a yard cover?
324 sq ft at 1", 162 at 2", 108 at 3".
Bulk or bags?
Bulk wins on price above roughly a yard; bags win on clean handling.
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Related calculators & sources
Filling beds first? Topsoil Calculator. Stone instead of mulch: River Rock Calculator. Base material and driveways: Gravel Calculator. The 324 rule and bag figures are cited at landscaping estimating figures; convert measurements with the area and volume converters.
Estimates for planning and purchasing. Not engineering or code-compliance advice — confirm structural work with your local building department.