Material Calculator This calculator will calculate the number of cubic yards of material you will need for your project. A cubic yard is 3ft x 3ft x 3ft. To determine the number of yards you will need for your project, enter the length, width and depth of your project area and then click the Calculate button. Approximate Number of Cubic Yards of Materials Needed: Circular Bed Calculator Mulch#4 /2 inch River bedBrick Chips 3/4#5 gravelSoilSandCrush & Run or ABCGravel # 57,67soil-mixes Approximate Number of Cubic Yards of Materials Needed: Triangle Bed Calculator Measure the two sides that meet at the 90° angle Approximate Number of Cubic Yards of Materials Needed: