Mulch Calculator
Example: 6 × 1.5 m at 8 cm = 0.7 m³
Calculate the amount of mulch needed for your garden beds, landscaping, or pathways. Enter the area dimensions and desired depth to find cubic yards or number of bags required. Includes cost estimates.
Cost by buying option
Volume Needed
Small Bags
Standard bag size
Large Bags
Large bag size
Bulk Cost
Before delivery
How We Calculate This
Volume = length × width × (depth in feet). Convert to cubic yards by dividing by 27. Coverage varies: 1 cubic yard covers 162 sq ft at 2" deep, 108 sq ft at 3" deep, 81 sq ft at 4" deep.
Methodology last reviewed: October 2022. How SparkCalc works
Sources: Penn State Extension: Mulching Landscape Trees · Iowa State University Extension: How Deep Should the Mulch Layer Be Around Trees and Shrubs? · Mississippi State University Extension: Mulch: A How-To for the Landscape
Frequently Asked Questions
How deep should mulch be?
2-3 inches for established beds, 3-4 inches for new installations. Too deep can harm plants and encourage pests. Replenish yearly as it decomposes.
Is bulk or bagged mulch cheaper?
Bulk is usually cheaper per cubic yard but requires delivery. Bags are convenient for small areas. Break-even is typically around 3-5 cubic yards depending on delivery cost.
How many bags are in a cubic yard?
A cubic yard equals 27 cubic feet. You need about 13.5 bags (2 cu ft each) or 9 bags (3 cu ft each) to equal one cubic yard.
Should I remove old mulch before adding new?
Not usually. Old decomposed mulch adds organic matter to soil. Remove only if diseased, moldy, or excessively deep (over 4 inches). Fluff existing mulch before adding new.
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