Skip to content

Mulch Calculator

Calculate how much mulch you need for your garden bed, in bags or bulk cubic yards, with cost comparison and depth presets.

Mulch coverage

Updates as you type
Bed shape
Shape ?
Area dimensions
Length
ft
12550100
Width
ft
12550100
Coverage area
Mulch depth
Depth ? 3 in
Pricing
Display volume as
Price per bag (2 cu ft) ?
$
$0$5$10$15
Price per cu yd (bulk) ?
$
$0$25$50$100

Depth sensitivity

How bags, volume, and cost scale with depth
Depth Volume Bags needed Bag cost (bagged, 2 cu ft) Bulk cost (per cu yd) Cost

Bag vs bulk — breakeven

Bag pricing Bulk pricing Breakeven —
Area Volume Bag cost (bagged, 2 cu ft) Bulk cost (per cu yd) Savings

Formula

V = A × D , N = V 2
V
Volume of mulch needed (cubic feet)
A
Coverage area — L × W for rectangles, π × (d/2)² for circles, ½ × b × h for triangles
D
Depth, converted from inches to feet (inches ÷ 12)
N
Bag count — cubic feet ÷ 2 (standard bag is 2 cu ft), rounded up
Worked example — your numbers
  1. Coverage area (A) =
  2. Depth (D) =
  3. Volume = A × D = cu ft
  4. Converted to cubic yards =
  5. Bags (2 cu ft each, rounded up) =
  6. Approx weight (~600 lb / cu yd) =
  7. Cheaper option =

2 cu ft is the industry-standard retail bag size. Bulk deliveries are priced per cubic yard (27 cu ft). Bulk tends to beat bags above ~2 cu yd of coverage — the breakdown above shows the actual crossover at your inputs. Order an extra 5–10% for settling and uneven ground.

Depth selection guide
2 inches
Refresh on top of existing mulch — restores color, minimal weed suppression
3 inches
Standard new application — good weed suppression, moisture retention, healthy plant beds
4 inches
Heavy weed suppression — recommended for new beds on bare soil, or areas with persistent weeds
6 inches
Winter insulation or soil building — use sparingly; too deep can smother plant roots year-round