Mulch Calculator: Bags or Cubic Yards

A 20 × 5 ft bed at 3 in deep takes 0.93 cu yd of mulch (25.0 cu ft): 13 bags of 2 cu ft or 9 bags of 3 cu ft. UF/IFAS: “One cubic yard of mulch will cover 324 square feet of ground at 1 inch deep, or 108 square feet at 3 inches deep”.

Set up for: mulch for beds or a playground · Different project?

How far a cubic yard goes

DepthSq ft per cu yd
1 in324
2 in162
3 in108
4 in81

27 cu ft × 12 ÷ depth; matches the Colorado State Extension table (81 sq ft at 4 in to 324 at 1 in).

How deep to spread it

How many bags of mulch in a yard

FAQ

How do I calculate how much mulch I need?

Square feet × depth in inches ÷ 324 = cubic yards (UF/IFAS). For bags, multiply cubic yards by 27 and divide by the bag size in cubic feet.

How much mulch for a playground?

Use the same calculation with the depth your playground surface guidance asks for; we don't set safety depths. Type the area and depth into the calculator.

Sources

Volumes only. ConcreteMath calculates volumes, bag counts, weights and your own cost figures. It gives no structural or engineering advice and never sizes footings, piers, slabs or rebar: those come from your plans, an engineer or your local building department. Bag counts are estimates from each maker's published yield; actual use varies with hole shape, uneven ground, waste and mixing. Bulk weights are published ranges; your supplier's figure wins.