Construction & Home
Mulch Calculator
This mulch calculator estimates how much mulch you need for landscape beds. It returns cubic feet, cubic yards, and estimated bag count.
Quick answer
Mulch volume is based on area times depth.
What this tells you
- •Mulch volume is based on area times depth.
- •Depth in inches is converted to feet for volume calculations.
- •Bag count is rounded up to ensure enough material.
How to Use
- 1Enter bed length and width in feet.
- 2Enter mulch depth in inches.
- 3Select bag size in cubic feet.
- 4Optionally add waste percentage.
- 5Calculate for total volume and bag count.
How It Works
Formula
Cubic Feet = Length x Width x Depth(ft)
Cubic Yards = Cubic Feet / 27
Bags = ceil((Cubic Feet with waste) / Bag Size)The calculator converts depth to feet, computes total volume, applies waste allowance, and rounds bag quantity up.
Calculation note: values are processed in the order shown above, using the current input units.
Worked Examples
Landscape bed estimate
Length20 ft
Width10 ft
Depth3 in
Bag2 cu ft
Waste10%
Result55.00 cu ft total, 28 bags
Common mistakes
- Using depth in feet instead of inches
- Forgetting waste allowance
- Rounding bag counts down
Frequently Asked Questions
A cubic yard is 27 cubic feet, so it takes 13.5 standard 2-cubic-foot bags to equal one cubic yard. If a bulk supplier quotes you 3 cubic yards, that is roughly 40-41 bags.
At a 3-inch depth, 100 square feet needs 25 cubic feet of mulch, which is 13 standard 2-cubic-foot bags (12.5 rounded up). At 2 inches, you need about 17 cubic feet, or 9 bags.
Cubic yards = square feet x depth in inches / 324. For example, a 200 sq ft bed at 3 inches deep needs 200 x 3 / 324 = 1.85 cubic yards.
Common mulch depth is 2-4 inches. Use 2 inches around delicate plants and up to 4 inches for weed suppression in open beds. Avoid piling mulch against trunks and stems.
You cannot buy partial bags, so rounding up avoids shortage.
Bulk delivery is usually cheaper above roughly 2-3 cubic yards (27-40 bags). Below that, bags are easier to transport and store. Use the cubic yard result to compare bulk quotes.
It estimates mulch calculator outputs using the visible inputs and formula assumptions on this page.