Bulk Material Mulch Calculator Length (in feet): Width (in feet): Depth: Please Select One 1/4 inch 1/2 inch 1 inch 2 inches 3 inches 4 inches 5 inches 6 inches Calculate You will need approximately: cubic yards of mulch.* or... (3 cubic foot) bags.* *Please round all values up to ensure proper coverage to pick up your bag today. Reset Formula for determining square foot areas:Circles: Area = Diameter² x 0.7854Triangles: Area = 1/2 Base x Height