How the mulch calculator works
Bed area is multiplied by mulch depth to get cubic feet. The calculator then applies your allowance and converts the result into cubic yards and complete bags.
volume = area × depth
Example
A 20 × 8 ft bed at 3 in deep requires 40 ft³ before allowance, or about 1.48 yd³.
Measure installed depth: settling, uneven beds, and existing mulch can change how much new material is actually needed.
Mulch calculator FAQ
How many bags are in a cubic yard?
It depends on the bag size. Enter the cubic-foot volume printed on the bag and the calculator converts the order.
What depth should I enter?
Use the actual planned installed depth for your project rather than a generic recommendation.
Why add an allowance?
An allowance can cover uneven grade, settling, measurement error, and small areas missed during measuring.