Mulch Calculator: How Many Cubic Yards Do I Need?
Estimate the cubic yards of mulch needed for garden beds, planting areas, and landscaping by entering the area and planned depth. Use the result to compare bulk mulch quantities and plan an order.
Calculate cubic yards of mulch
The ATHENA Mulch Calculator uses length, width, and depth to estimate cubic yards and adds a 10% planning allowance to the recommended order.
How to calculate mulch in cubic yards
For a rectangular area, multiply length by width to get square feet. Then multiply the area by the planned depth in feet to get cubic feet, and divide by 27 to convert cubic feet to cubic yards.
Cubic yards = length × width × depth in feet ÷ 27
When your depth is entered in inches, divide the inch measurement by 12 before using the formula.
Example: a 20 × 10 ft bed at 3 inches
A 20 × 10 ft bed has 200 square feet. At 3 inches deep, the depth is 0.25 feet, so the project needs about 1.85 cubic yards before any planning allowance. With ATHENA's 10% planning allowance, the planning quantity is about 2.04 cubic yards.
How to handle irregular beds
Break an irregular landscape bed into smaller rectangles or other simple sections. Calculate each section separately, then add the cubic-yard results together before planning the order.
How much mulch should I order?
Use the calculated volume as the starting point, then review the product depth and coverage requirements for the exact mulch you are buying. Coverage can vary by material, depth, compaction, and how the product is delivered.
Bulk mulch vs. bags
Bulk mulch is commonly quoted by cubic yard. Bagged mulch is usually sold by the individual bag, so a cubic-yard estimate must be converted using the bag's stated coverage or volume. See How Many Bags of Mulch Do I Need? for the bag-planning method.
Ready to calculate?
Open the free Mulch Calculator or read How Much Mulch Do I Need? for the broader planning guide.
Compare landscape mulch & garden materials on Amazon (paid link)
Important note
Actual coverage varies by mulch type, depth, compaction, and delivery method. Use the calculator as a planning estimate and confirm the final quantity with your supplier or product information.
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