How to calculate gravel
Gravel is estimated by volume, then converted to weight for ordering. Multiply the length, width, and depth in feet to get cubic feet, divide by 27 for cubic yards, then multiply by the gravel's density to get tons:
Cubic yards = (Length ft × Width ft × Depth ft) ÷ 27
Tons = Cubic yards × density (≈ 1.4 tons/cu yd)
A 20 ft × 10 ft area covered 2 inches deep works out to about 1.23 cubic yards, or roughly 1.7 tons of typical gravel.
How deep to lay gravel
- Garden paths & walkways: about 2 inches over a firm base.
- Driveways: 4–6 inches total, often in a coarse base layer plus a finer top.
- Patio or shed base: 4 inches of compacted gravel is a common sub-base.
Weight and ordering
A cubic yard of gravel weighs roughly 2,800 pounds (1.4 tons), but it varies from about 2,400 to 3,000 pounds with the stone type and moisture. If your supplier quotes a different density, enter it in the field above. Add a small overage so you are not left short while spreading and compacting.
Frequently asked questions
How do I calculate how much gravel I need?
Multiply the area length by the width by the depth, with all measurements in feet, to get the volume in cubic feet, then divide by 27 for cubic yards. Depth is usually in inches, so divide it by 12 first. A 20 ft × 10 ft area at 2 inches deep is 20 × 10 × 0.167 = 33.3 cubic feet, or about 1.23 cubic yards.
How many tons of gravel are in a cubic yard?
About 1.4 tons. A cubic yard of typical gravel weighs roughly 2,800 pounds, though it ranges from about 2,400 to 3,000 pounds depending on the stone type, size, and moisture. Gravel is often sold by the ton, so this conversion lets you order the right amount.
How deep should a gravel layer be?
For walkways and garden paths, 2 inches over a base is common. Driveways usually need 4–6 inches, often built in layers with a coarser base and finer top. For a new driveway over soft ground, plan on a deeper total build-up.
Is gravel sold by the ton or the yard?
Both. Bulk gravel is commonly priced per ton or per cubic yard, while bagged gravel is sold by weight or volume per bag. This calculator gives you cubic yards, cubic feet, and tons so you can match whichever unit your supplier uses.
Disclaimer: Gravel density varies by material, so weight is an estimate. Confirm coverage and pricing with your supplier before ordering.