Calculating Mulch, Soil and Sand Coverage:
To figure out how many cubic yards you will need, first you need to figure out how much area you want to cover and how deep you want the material.
27 cubic feet = 1 cubic yard
1 cubic yard of material will cover approximately 100 square feet 3″ deep. For soil and sand caluclations, add an extra 25% to allow for settling and packing.