CROCODILIAN
Mulch calculator

Mulch calculator

Bed size and depth to cubic yards and bags — for rectangular beds and circular tree rings.

Area shape
ft
ft
in
$

Pre-filled example: a 10 × 10 ft bed at 3 inches — the middle of the extension-recommended 2–4" range.

Area
100 ft²
Volume
25.0 ft³
You need
0.93cubic yards
Order (rounded up)1.00 yd³
2 cu ft bags13
3 cu ft bags9
Estimates for planning — confirm quantities with your supplier.
Real-world quantities vary with moisture, compaction, cuts, and site conditions. These calculators use standard formulas and published constants (see the About page for sources); order with a sensible allowance and confirm with your supplier or contractor.

How deep to mulch

University of Minnesota Extension’s guidance: “Apply mulch at a depth of 2 to 4 inches to balance weed suppression with adequate soil aeration.” UF/IFAS Florida-Friendly Landscaping recommends 2–3 inches, replenished as it decomposes. Below about an inch, weeds break through; above 4 inches, roots can suffocate and perennial crowns rot.

Around trees, spread the ring wide but keep roughly 6 inches next to the trunk mulch-free — moisture held against bark invites rot and insects. Use the circle mode above with the ring’s outer diameter, then subtract a small circle for the clear zone if you want to be precise.

Coverage per cubic yard

What 1 cubic yard of mulch covers, and the bag equivalent
Depth1 yd³ covers2 cu ft bags / yd³3 cu ft bags / yd³
2"162 ft²13.59
3"108 ft²13.59
4"81 ft²13.59

Bag counts per cubic yard are constant (27 ft³ ÷ bag size); coverage falls as depth rises. Worked example: a 10 × 10 ft bed at 3 inches needs 25 ft³ = 0.93 yd³ ≈ 13 two-cubic-foot bags.

Frequently asked questions