Mulch Calculator
Find out how many cubic yards, or 2 cu ft bags, of mulch cover a garden bed at the depth you choose.
Calculator
| Cubic yards (exact) | 0.93 yd³ |
|---|---|
| Cubic feet | 25.0 ft³ |
| 2 cu ft bags | 14 bags |
How it is calculated
10 ft × 10 ft × 3 in ÷ 12 = 25.0 cubic feet = 0.93 cubic yards. Add 5% for settling and uneven ground: 0.97 cubic yards.
About this calculator
Mulch holds moisture, moderates soil temperature and suppresses weeds. How much you need depends on the area of the bed and the depth you spread it. A layer of around two to three inches is a common recommendation; much deeper layers can hold too much water and starve roots of air.
Bulk mulch is sold by the cubic yard and bagged mulch by the cubic foot, commonly in 2 cubic foot bags. One cubic yard is 27 cubic feet, or 13.5 two-cubic-foot bags. Bulk delivery is usually cheaper per yard once you need several yards, while bags are easier to handle for small beds.
Worked examples
| Project | Cubic yards to order (+5%) | Rough cost |
|---|---|---|
| a 10x10 ft bed mulched 3 in deep | 0.97 yd³ | $29.17 – $68.06 |
| a 10x20 ft bed mulched 3 in deep | 1.94 yd³ | $58.33 – $136 |
| a 20x20 ft bed mulched 2 in deep | 2.59 yd³ | $77.78 – $181 |
| a 30x40 ft bed mulched 3 in deep | 11.67 yd³ | $350 – $817 |
Buying notes
- Subtract areas that will not be mulched, such as paving, large rocks or the ground right around trunks.
- For curved beds, estimate an average width along the length, or split the bed into rectangles and add the results.
- Keep mulch a few inches away from tree trunks and house siding.
- Bulk suppliers often round deliveries to whole or half yards; ask what they offer.
Quick answers by size
Click a size for the exact quantity and cost.
How to measure and use this calculator
- Measure the bed's length and average width.
- Choose a depth. Two to three inches suits most beds.
- Read cubic yards or the number of 2 cu ft bags.
- Pull back old mulch before topping up so beds do not get too deep.
Common mistakes
- Piling mulch against tree trunks (the 'mulch volcano').
- Going deeper than three inches, which can suffocate roots.
- Buying bags for a large area when bulk delivery would cost less.
Tips
- Two to three inches is enough for most beds; deeper mulch can smother roots.
- One cubic yard covers about 108 sq ft at 3 inches deep.
- Bulk delivery is usually cheaper than bags once you need more than about 3 cubic yards.
Frequently asked questions
How many bags of mulch in a cubic yard?
A cubic yard equals 13.5 bags of 2 cubic feet each.
How many square feet does one cubic yard of mulch cover?
One cubic yard is 27 cubic feet, so it covers about 108 sq ft at 3 inches deep, about 162 sq ft at 2 inches and about 81 sq ft at 4 inches.
Can I put new mulch over old mulch?
A thin top-up is fine. If the old layer is already a few inches deep, rake it loose rather than adding more, so the total does not get too thick.