Mulch Calculator
Calculate how many bags or cubic yards of mulch a garden bed needs.
Last updated · View algorithm, constants and default inputs (JSON)
About this calculator
Estimate mulch volume and bag count from the bed dimensions, depth and bag size. The result assumes an even layer; actual coverage varies with the product, settled depth and ground shape. Check the bag coverage and the depth suited to your plants before ordering.
Worked example
calculated with the default values below
Bed length 30 ft · Bed width 6 ft · Depth 3 in · Bag size 2 cu ft · Price per bag 4 $ Bed area 180 sq ft · Mulch volume 45.0 cu ft · Mulch volume 1.67 cu yd · Bags needed 23 · Estimated cost 92.00 $
General background references
Disclaimer
These calculators provide planning estimates only. Building codes, wiring regulations and safety requirements differ by country and change over time, and nothing here replaces a licensed professional or a permit. For structural, electrical or gas work, follow local code and have the installation inspected.
Implementation source
This record describes the implementation used by this page. It is not independent validation. External references, when available, support only the stated formula or definition; estimates and custom rules retain their own assumptions.
Formula and variables
B = ceil(L × W × d / (12 × s))
- B
- number of bags
- L
- bed length, ft
- W
- bed width, ft
- d
- depth, inches
- s
- bag size, cu ft
Volume = L×W×d/12 ft³ = L×W×d/(12×27) yd³; default s = 2 ft³; cost = B × price per bag.
Frequently asked questions
What affects the mulch coverage estimate?
Estimate mulch volume and bag count from the bed dimensions, depth and bag size. The result assumes an even layer; actual coverage varies with the product, settled depth and ground shape. Check the bag coverage and the depth suited to your plants before ordering.