Mulch Bag Calculator
Find exactly how many 1.5, 2 or 3 cu ft bags of mulch to buy.
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Currency: Amounts are calculated in the currency you select; this site does not convert between currencies and does not use live exchange rates.
What this tool does
Built for bagged mulch shoppers, this calculator converts your bed size and depth into the exact number of bags for the bag size on the shelf, plus the bulk equivalent for comparison.
How to use the Mulch Bag Calculator
- Measure the bed length and width.
- Enter the mulch depth you want.
- Choose the bag size you plan to buy.
- Enter the bulk price per cubic yard to compare.
- Buy the bags shown or order the bulk yards.
Formula
cu ft = L × W × (D ÷ 12); yd³ = cu ft ÷ 27; bags = ⌈cu ft ÷ bag size⌉
- L, W
- Length and width (ft)
- D
- Depth (in)
- bag size
- Bag volume in cu ft
Worked example
A 20 × 10 ft bed at 2 in deep using 2 cu ft bags.
Inputs
- Length20 ft
- Width10 ft
- Depth2 in
- Bag size2 cu ft
- Price per cubic yard (bulk)$38
Result
- Mulch needed1.23 cu yd
- Bags (2 cu ft)17
- Volume33.33 cu ft
- Bulk cost estimate$46.91
Mulch coverage by depth
| Depth | Coverage of 1 cu yd | Coverage of a 2 cu ft bag |
|---|---|---|
| 1 in | 324 sq ft | 24.0 sq ft |
| 2 in | 162 sq ft | 12.0 sq ft |
| 3 in | 108 sq ft | 8.0 sq ft |
| 4 in | 81 sq ft | 6.0 sq ft |
| 6 in | 54 sq ft | 4.0 sq ft |
Results explained
- Mulch needed
- Cubic yards for a bulk delivery.
- Bags
- Bags to buy, rounded up to whole bags.
- Volume
- Total cubic feet.
- Bulk cost
- Yards × price per yard, excluding delivery.
Frequently asked questions
At 2 in deep, 100 sq ft needs 16.7 cu ft — 9 bags of 2 cu ft.
12 sq ft at 2 in, 8 sq ft at 3 in, 6 sq ft at 4 in.
Nine — a cubic yard is 27 cu ft.
Add 5–10% if the bed has uneven ground or you're topping up old mulch unevenly.
Yes — common sizes are 1.5, 2 and 3 cu ft. Always check the bag label.