The coverage formula
square feet covered = cubic feet × 12 ÷ depth (in)
square feet per cubic yard = 324 ÷ depth (in)
A cubic yard is 27 cubic feet. Spread 1 inch thick (1/12 of a foot), 27 cubic feet covers 27 × 12 = 324 square feet. At 3 inches it covers a third of that: 108 square feet.
How much does a yard of mulch cover?
| Depth | One cubic yard covers | About the size of |
|---|---|---|
| 1 inch | 324 sq ft | 18 × 18 ft |
| 2 inches | 162 sq ft | 18 × 9 ft |
| 3 inches | 108 sq ft | 12 × 9 ft |
| 4 inches | 81 sq ft | 9 × 9 ft |
| 6 inches | 54 sq ft | 9 × 6 ft |
Coverage of larger orders
| Cubic yards | At 2 in | At 3 in | At 4 in |
|---|---|---|---|
| 0.5 | 81 sq ft | 54 sq ft | 40.5 sq ft |
| 1 | 162 sq ft | 108 sq ft | 81 sq ft |
| 2 | 324 sq ft | 216 sq ft | 162 sq ft |
| 3 | 486 sq ft | 324 sq ft | 243 sq ft |
| 5 | 810 sq ft | 540 sq ft | 405 sq ft |
| 10 | 1,620 sq ft | 1,080 sq ft | 810 sq ft |
| 20 | 3,240 sq ft | 2,160 sq ft | 1,620 sq ft |
How much does a bag of mulch cover?
| Depth | 1.5 cu ft bag | 2 cu ft bag | 3 cu ft bag |
|---|---|---|---|
| 1 inch | 18 sq ft | 24 sq ft | 36 sq ft |
| 2 inches | 9 sq ft | 12 sq ft | 18 sq ft |
| 3 inches | 6 sq ft | 8 sq ft | 12 sq ft |
| 4 inches | 4.5 sq ft | 6 sq ft | 9 sq ft |
The mulch bag calculator turns your bed sizes straight into a bag count.
Mulch per square foot
Sometimes it’s easier to think per square foot, especially when a supplier quotes “a yard covers X”:
| Depth | Cubic feet per sq ft | Cubic yards per 100 sq ft |
|---|---|---|
| 1 inch | 0.083 | 0.31 |
| 2 inches | 0.167 | 0.62 |
| 3 inches | 0.25 | 0.93 |
| 4 inches | 0.333 | 1.23 |
So a 100 sq ft bed at 3 inches needs just under 1 cubic yard, and every extra inch of depth on 100 sq ft adds about 0.31 yards.
Estimating mulch coverage on the ground
Charts are exact arithmetic, but mulch isn’t perfectly uniform. A few things push real coverage below the chart:
- Settling. Fresh shredded mulch is fluffy. After a couple of rains it can sit noticeably lower than the day you spread it.
- Uneven beds. Low spots, the dip along an edging strip, and soil mounded around plants all take extra.
- Thick edges. It’s easy to dump extra along the front edge where it shows.
That’s why the calculator lets you add an extra percentage, and why rounding up to the next half yard or the next bag is normal. If you want an exact top-up, measure the existing depth first; the measuring guide shows how.
If a product lists its own coverage on the bag or the supplier's website, use that. Products differ in how loosely they're packed.
Questions people ask
- How much does a yard of mulch cover?
- One cubic yard covers 324 square feet at 1 inch deep, 162 square feet at 2 inches, 108 square feet at 3 inches and 81 square feet at 4 inches.
- How much mulch do I need per square foot?
- At 3 inches deep, each square foot needs 0.25 cubic feet, or about 0.0093 cubic yards. At 2 inches it needs about 0.17 cubic feet.
- How much does a bag of mulch cover?
- A 2 cubic foot bag covers about 12 square feet at 2 inches or 8 square feet at 3 inches. A 3 cubic foot bag covers 18 or 12 square feet.
- How much will 10 cubic yards of mulch cover?
- About 1,620 square feet at 2 inches, 1,080 square feet at 3 inches and 810 square feet at 4 inches.
- Why does my mulch not cover as much as the chart says?
- Mulch settles after it's spread and watered, beds are rarely perfectly level, and people tend to spread thicker than they planned near edges. Expect real coverage to land a little under the chart.