Gravel Calculator

Gravel is sold by volume (cubic yards) or by weight (tons), so the calculator does both. First it finds the area in square feet: length × width for a rectangle, or π × (diameter ÷ 2)² for a circle. Then it multiplies by the depth in feet, because depth is usually quoted in inches, and divides by 12. That gives cubic feet. There are exactly 27 cubic feet in a cubic yard (3 ft × 3 ft × 3 ft), so cubic feet ÷ 27 = cubic yards.

Worked example: a 20 × 10 ft path at 3 inches deep is 200 sq ft × 0.25 ft = 50 cubic feet. Add 10% for compaction and spillage and you have 55 cubic feet, or 2.04 cubic yards.

Weight depends on the stone. The calculator uses typical loose bulk densities: about 1.35 tons per cubic yard for crushed stone and river rock, 1.4 for pea gravel, and 1.5 for crusher run or road base, which packs its fines between the larger pieces. The 2.04 cubic yards above weigh about 2.75 tons as crushed stone or 3.06 tons as crusher run.

These are estimates. Wet stone is heavier, and quarries publish their own figures, so if your supplier sells by the ton, ask for their tons-per-yard number and use it to check the order. NIST lists the unit relationship for reference: one short ton per cubic yard is about 1,187 kilograms per cubic meter.