Mulch Calculator
Enter area dimensions and desired depth to find mulch quantity.
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Coverage Per Cubic Yard
| Depth | Coverage (sq ft / cu yd) |
|---|---|
| 1" | 324 sq ft |
| 2" | 162 sq ft |
| 3" | 108 sq ft |
| 4" | 81 sq ft |
| 6" | 54 sq ft |
How Much Mulch Do I Need?
The recommended mulch depth is 2-4 inches for most garden beds. Too thin and weeds push through; too thick and it can suffocate plant roots and trap excess moisture.
Measure the length and width of your mulch area, multiply to get square feet, then multiply by the depth in feet to get cubic feet. Divide by 27 for cubic yards. Most bagged mulch comes in 2 cubic foot bags.
Mulch volume = area × depth (in feet). A 200 sq ft garden bed at 3-inch mulch depth: 200 × 0.25 = 50 cubic feet = 50/27 ≈ 1.85 cubic yards. Bagged mulch is sold in 2 cu ft bags; bulk is by the cubic yard. For 50 cubic feet: 25 bags or ≈1.85 yards of bulk.
Recommended depths by mulch type: wood chips 3–4 inches, shredded bark 2–3 inches, straw 4–6 inches, gravel/rock 2–3 inches. Don't exceed 4 inches for wood products — deeper mulch can mat and prevent water penetration, and it may harbor fungal issues (mulch volcano around tree trunks is a common damaging error).
Weed suppression works best with a consistent 2–3 inch layer over cardboard (sheet mulching) or 4–6 inches without cardboard. Weeds with deep tap roots (thistle, dandelion) will penetrate most mulch depths; hand-pull them before mulching.
Organic mulch (wood chips, straw, shredded leaves) decomposes over the season, improving soil structure. Plan to reapply annually. Inorganic mulch (rock, gravel) is permanent but doesn't improve soil; it heats soil more in summer, which can stress shallow-rooted plants.
See also: Soil Volume Calculator · Bed Area Calculator