Calculating mulch is easier than you think.
Most of our clients use: (LxW)/150= cubic yards (at 2” coverage)
To see how many bags you don't need to lug home when you buy bulk Cubic Yards x 13.5 = Bags (Round up to the nearest bag) (There are 27 cubic feet in a cubic yard, but 2 cubic feet in each bag = 13.5)
Square, rectangle, and parallelogram Area = LxW
Circular Area = 3.14 x radius x radius
Triangular Area = (Base x Height)/2