Mulch calculator: how many bags of mulch do I need?
13 bags
0.93 cubic yards · 25 cubic feet · for 10 × 10 ft at 3 in
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3/8 or 10' 6".
13 bags
0.93 cubic yards · 25 cubic feet
A 10 by 10 ft bed at 3 inches deep needs 0.93 cubic yards of mulch, which is 25 cubic feet, or 13 bags of the 2 cubic foot size. A full cubic yard is 13.5 of those bags, so 14 to buy.
A worked example
A 22 by 4 ft foundation border at 3 inches deep, in 2 cu ft bags needs 11 bags of 2 cu ft. 22 cubic feet. At 3 inches a 2 cubic foot bag covers 8 square feet, and the border is 88 square feet, so 11 bags is the count.
How deep should mulch be?
Penn State Extension recommends a 2- to 4-inch layer of organic mulch and no more, using less on poorly drained soil, because a layer thicker than 4 inches can starve the roots of air and water. Two inches tops up an established bed; three is a common choice for a new bed over bare soil. Enter the depth you want above and the calculator returns the cubic yards and the bag count. Keep mulch off the trunk of a tree or shrub so the root flare still shows.
How much mulch do I need for a playground?
Lay wood chips 12 inches deep. The CPSC Public Playground Safety Handbook rates 9 inches of wood chips for falls from up to 10 feet, and because loose fill compresses at least 25% with use and weather, it says to start at 12 inches so that 9 remain. It sets 9 inches as the floor for every loose fill except shredded rubber, which goes down at 6. A 15 by 24 ft play area at 12 inches is 360 cubic feet: 13.3 cubic yards in bulk, or 180 bags of 2 cubic feet. Enter 12 as the depth above for a play area, four times the 3 inches of a garden bed.
What else it is called
Mulch is sold as bark mulch, wood chips, shredded hardwood, pine bark and pine straw. The volume you need is the same for all of them because it is geometry; what changes is how fast each breaks down and the price. In bulk it is sold by the cubic yard.
Common sizes
| Area | 2 in deep | 3 in deep | 4 in deep | 6 in deep |
|---|---|---|---|---|
| 8 × 8 ft | 0.40 | 0.60 | 0.80 | 1.19 |
| 10 × 10 ft | 0.62 | 0.93 | 1.24 | 1.86 |
| 10 × 12 ft | 0.75 | 1.12 | 1.49 | 2.23 |
| 12 × 12 ft | 0.89 | 1.34 | 1.78 | 2.67 |
| 12 × 16 ft | 1.19 | 1.78 | 2.38 | 3.56 |
| 16 × 20 ft | 1.98 | 2.97 | 3.96 | 5.93 |
| 20 × 20 ft | 2.47 | 3.71 | 4.94 | 7.41 |
Cubic yards, rounded up to two decimals. Round up again to what your supplier will deliver.
Where the numbers come from
- Bag sizes: Scotts Nature Scapes Color Enhanced Mulch is sold in 1.5 and 2 cubic foot bags, per the manufacturer's product page. Read September 29, 2026. Source
- Volume is geometry: 1 cubic yard = 27 cubic feet, exact by definition, so a cubic yard of mulch is 13.5 of the 2 cubic foot bags, 14 to buy. At 3 inches deep a 2 cubic foot bag covers 8 square feet (2 ÷ 0.25).
- Depth: Penn State Extension, Mulching Landscape Trees, recommends a 2- to 4-inch layer of organic mulch and no more, using less on poorly drained soil, because more than 4 inches can harm the root system. Read September 29, 2026. Source
- Playground depth: U.S. Consumer Product Safety Commission, Public Playground Safety Handbook (Pub. 325), Table 2: 9 inches of wood chips protects to a fall height of 10 feet. Loose-fill materials compress at least 25% over time, so where 9 inches of wood chips are required the initial fill level is 12 inches; never less than 9 inches of loose fill except shredded/recycled rubber (6 inches recommended). Read October 28, 2026. Data sheet (PDF)
Bag counts are rounded up. Mulch settles and breaks down over a season, so an established bed usually needs only a top-up to hold its depth, not a full new layer.
By Javier Miralles · Last updated . How this site is made.
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