A. You can use the handy Garden Calculators on our website to determine the amount of aggregates you will need for your job. Simply enter the length, width and depth of each material to see how many cubic yards are required. Remember, all materials (for interlocking or planting) compact over time. It is always a good idea to add a few inches to your final depth to allow for compaction. For example, using 3/4 crusher (a mixture of gravel and sand) for the base of your walkway will require just over 6 inches of material before compaction for a final base of only four inches. For every one inch of material, it compacts to three-quarters of an inch.