Base and drainage

Gravel Calculator

Calculate cubic yards and approximate tons for a compacted gravel layer. Enter the job dimensions below, then review the guide before ordering.

Gravel calculation formula

length x width x (depth in inches / 12) / 27 = cubic yards

Worked example: A 30 ft by 10 ft area at 4 inches deep is 100 cu ft before allowance. With 15% for compaction and grading, the result is 4.26 cu yd, approximately 6 tons at 1.4 tons per cubic yard.

Loose depth and compacted depth

Plans often specify a compacted depth, but material arrives loose. The allowance helps account for settlement, compaction, and minor grade variation. Compact aggregate in appropriate lifts rather than placing a thick layer all at once.

Converting volume to weight

Stone density varies with rock type, gradation, moisture, and void space. The calculator uses a general estimate of 1.4 tons per cubic yard. Ask the supplier for the actual tons-per-yard factor for the selected material.

Measure irregular areas

Divide drives and paths into simple rectangles. For tapered sections, use the average width. Keep excavation volume separate from aggregate volume if geotextile, sand, or multiple base courses are part of the assembly.

Before placing an order

Recheck field measurements, confirm the selected product's actual package coverage or density, and ask the supplier about order increments, minimum quantities, delivery limits, and return rules. Keep unlike products and assemblies in separate calculations.