Mulch Calculator
Find how much mulch you need — enter your bed area and depth to get the cubic yards, the number of 2 cu ft bags, and an estimated cost, with a coverage breakdown.
United States — national average · 2026 prices
Material only unless stated as installed. Excludes tax, permits and local labour. Verify with local suppliers — see how we calculate.
How this calculator works
Every figure above comes from the formula below, applied to the assumptions listed. Nothing is looked up from a hidden table — you can reproduce the result by hand.
Formula
cubic yards = area (sq ft) × depth (in) ÷ 324
cubic feet = area × depth ÷ 12 · bags = cubic feet ÷ 2 cu ft, rounded up
coverage per cubic yard = 324 ÷ depth (in), in square feet
Assumptions & limits
- The 324 divisor is exact, not a fudge: a cubic yard is 27 cu ft and there are 12 inches per foot, so 27 × 12 = 324.
- Bags are the standard 2 cubic foot size. Some brands sell 1.5 or 3 cu ft bags — check the label before comparing prices.
- Bulk mulch is priced at $35 per cubic yard and bags at $4 each, so the comparison shows the bulk break-even (usually around 6–8 bags).
- Mulch is sold by loose volume and settles roughly 10–20% after watering. No settling allowance is added, so measure the depth you want to end up with.
- Default depth is 3 inches. Keep mulch pulled back from trunks and stems — depth against bark causes rot, whatever the volume says.
Worked example
A 500 sq ft planting bed at 3 inches deep
- Cubic yards = 500 × 3 ÷ 324 = 4.63 yd³
- Cubic feet = 500 × 3 ÷ 12 = 125 cu ft
- Bags = 125 ÷ 2 = 62.5 → 63 bags
- Coverage = 324 ÷ 3 = 108 sq ft per cubic yard
Result:4.63 cubic yards — about $162 bulk versus $252 in bags, so this job is firmly bulk territory.
Built and maintained by Christoph Ballmer, Honeygoat GmbH
Method and constants last checked against the calculator code on August 17, 2026. Independent trade review is not yet in place for this calculator — see how we handle review.
Read the site-wide calculation methodology · estimate vs. quote and safety limits
How much mulch do I need?
Mulch is ordered by volume — cubic yards in bulk or 2 cubic-foot bags. Find the amount by multiplying your bed area in square feet by the depth in inches, then dividing by 324. The calculator above does this and converts it into bags and a cost so you can compare bulk against bagged.
cubic yards = area (sq ft) × depth (in) ÷ 324 · bags = cubic feet ÷ 2
Mulch coverage per cubic yard
| Depth | Coverage per yd³ | Bags (2 cu ft) per yd³ |
|---|---|---|
| 1 inch | 324 sq ft | 13.5 |
| 2 inches | 162 sq ft | 13.5 |
| 3 inches | 108 sq ft | 13.5 |
| 4 inches | 81 sq ft | 13.5 |
A cubic yard always equals 13.5 of the 2 cu ft bags; the depth changes the area it covers.
Two to three inches is right for most beds. For other bulk materials, see the soil calculator, the sand calculator, or the cubic yards calculator.
What mulch costs in 2026
| Mulch type | Bulk $/yd³ | Per 2 cu ft bag |
|---|---|---|
| Shredded hardwood | $30–$45 | $3–$5 |
| Dyed (black/brown/red) | $35–$50 | $4–$6 |
| Cedar / cypress | $40–$60 | $5–$7 |
| Pine bark nuggets | $30–$50 | $4–$6 |
The bulk break-even sits around 6–8 bags: past that, a yard delivered is cheaper per cubic foot than bags, and one yard replaces 13.5 of them — fewer plastic sacks to haul and empty.
Common mistakes
- Volcano mulching. Mulch piled against trunks and stems holds moisture on the bark and invites rot and borers. Keep it pulled back a few inches — a donut, never a volcano.
- Going deeper than 4 inches. Thick mulch sheds water instead of passing it and can suffocate shallow roots. Two to three inches does the weed-and-moisture job.
- Landscape fabric under organic mulch. The mulch decomposes into soil ON TOP of the fabric, and weeds root happily in that layer while the fabric blocks the bed below.
- Ignoring settling. Fresh mulch settles roughly 10–20% in the first weeks — measure the depth you want to end up with, not the fluffed depth off the truck.
- Buying bags for a whole yard. At 13.5 bags per cubic yard, a three-yard job is 40 bags — order bulk.
Topping beds yearly? One inch of refresh is usually enough — a third of the first-year quantity. For stone beds that never decompose, run the same math in the gravel calculator.
Prices are 2026 national ranges and vary by region and season — spring quotes run highest. Confirm delivered pricing with a local supplier.
Frequently asked questions
How much mulch do I need?
Multiply the bed area in square feet by the depth in inches, then divide by 324 to get cubic yards. For example, 500 sq ft at 3 inches deep is 500 × 3 ÷ 324 ≈ 4.6 cubic yards. The calculator above does this and also converts it into 2 cu ft bags with a cost estimate.
How many bags of mulch are in a yard?
A cubic yard is 27 cubic feet, so it equals about 13.5 of the standard 2 cubic-foot bags. Bulk mulch by the yard is usually cheaper than bags once you need more than roughly 6–8 bags, which is where the calculator helps you compare.
How deep should mulch be?
Two to three inches is right for most beds — enough to suppress weeds and hold moisture without smothering roots. Three to four inches suits new beds or coarse mulch, while keeping it thinner and pulled back from trunks and stems avoids rot. The calculator defaults to 3 inches.
How much does a yard of mulch cover?
One cubic yard covers about 324 square feet at 1 inch deep, 162 sq ft at 2 inches, or 108 sq ft at 3 inches. Deeper mulch covers less area per yard. Enter your depth above and the calculator shows the coverage and yards for your bed.