Depth controls coverage
A cubic yard is 27 cubic feet. Spread it one inch deep and it covers 324 square feet. Spread it three inches deep and it covers 108 square feet. A greater depth needs more material for the same area.
The coverage formula
Coverage in square feet = cubic yards × 324 ÷ depth in inches. For a volume of 1 cubic yard: 1 inch covers 324 sq ft; 2 inches covers 162 sq ft; 3 inches covers 108 sq ft; 4 inches covers 81 sq ft; 6 inches covers 54 sq ft. These figures assume an even layer without compaction or losses.
Working backward from your space
For a 200-square-foot area at 3 inches deep, divide 200 × 3 by 324. The result is approximately 1.852 cubic yards before an allowance. With a 5% allowance, the estimate becomes 1.944 cubic yards. Confirm the supplier’s order increment before rounding to a purchase quantity.
Use the additional depth for a top-up
If an existing layer measures 1 inch and your desired finished layer is 3 inches, the additional depth is 2 inches. For 200 square feet, this needs about 1.235 cubic yards before allowance. Measuring what is already there can avoid a substantial over-order.
Coverage is a planning estimate
Loose, delivered material can settle or compact. Ground can slope, edges can be irregular and depth can vary. The arithmetic is exact for the dimensions you enter, but a real order is only as accurate as those measurements and material assumptions.
Put your measurements to work.
Calculate volume, adjust your allowance and save a link to your estimate.
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