Home & build
Estimate gravel volume and purchase quantity for a project.
Enter your numbers to see the answer.
Gravel calculator guide
Gravel is sold by the cubic yard or by the ton, while a driveway, path, or drainage bed is measured with a tape in feet and inches. This calculator bridges the two: it multiplies length and width in feet by depth in inches converted to feet, adds a waste allowance for compaction and uneven ground, and reports cubic yards along with cubic feet and cubic metres. Use the compacted finished depth you want, and remember that crushed stone loses about 10–15% of its loose volume when rolled or driven on, which is what the default allowance covers. To turn the result into a purchase weight, multiply cubic yards by the supplier’s bulk density; most loose crushed stone and pea gravel run about 1.4 tonnes per cubic metre, or roughly 2,800 lb (1.4 short tons) per cubic yard, and damp material weighs more. The result is a planning estimate: confirm density and minimum delivery with the quarry.
Base volume (ft³) = length (ft) × width (ft) × depth (in) ÷ 12. Volume (yd³) = base volume × (1 + waste ÷ 100) ÷ 27. Weight (tons) ≈ yd³ × 1.4.
Worked example: a 20 ft × 10 ft parking pad topped with 3 in of gravel has a base volume of 20 × 10 × (3 ÷ 12) = 50 ft³, which is 50 ÷ 27 = 1.85 yd³. Adding the 10% allowance for compaction gives 50 × 1.10 = 55 ft³, or 55 ÷ 27 = 2.04 yd³ (1.56 m³). At a typical bulk density of 2,800 lb per cubic yard that is about 2.04 × 2,800 = 5,712 lb, or 2.86 short tons, so you would order 3 tons. The calculator displays 2.04 yd³.
Length and width are feet, depth is inches, and the result is cubic yards with cubic feet and cubic metres alongside. Convert inches of length to decimal feet before entering (6 in = 0.5 ft). A cubic yard is 27 cubic feet or 0.7646 m³. Suppliers quoting tons need a density: use 1.4 t/m³ or 2,800 lb/yd³ for crushed stone unless the quarry gives its own figure, and note US short tons are 2,000 lb.
The gravel calculator returns a quantity to buy, not a guarantee of coverage. Substrate condition, waste from cuts, spillage, and settling all push real consumption above the theoretical figure, which is why most trades order a margin on top. Check the coverage rate printed on the product you actually purchase, because it varies between brands and mixes. On this page the figure rests entirely on length, width, depth and waste allowance, so start there if the gravel calculator returns something you did not expect.
Good to know: the results table shares its layout with the concrete tool, so the 80 lb bag row uses a concrete bag yield and does not describe gravel, which is bought by the yard or ton. Enter the compacted depth you want to end up with, not the loose depth you spread. A 3 in top layer is typical for a driveway surface; a new driveway also needs a 4–6 in base layer of larger stone, which is a separate calculation. Do not convert yards to tons with a density for sand or soil.
Construction quantities are planning estimates. Confirm product yield, waste, site conditions, structural requirements, and local code with the supplier or qualified professional.
Sources
How it works
Estimate gravel volume and purchase quantity for a project. This tool explains the calculation so you can adjust the assumptions to match your situation.
Worked example
With Length = 20 ft · Width = 10 ft · Depth = 3 in · Waste allowance = 10 % → 2.04 yd³ (recommended slab volume including waste). Change an input above and this example updates with your numbers.
Common questions
At 3 inches deep a 20 × 10 ft area needs 1.85 cubic yards of gravel before allowance and about 2.04 cubic yards with 10% added for compaction. At 2,800 lb per cubic yard that is about 2.86 tons, so order 3 tons.
Loose crushed stone and pea gravel weigh roughly 2,800 lb per cubic yard, or about 1.4 US short tons. Wet or fine material can approach 3,000 lb. Multiply the cubic yards from this page by the density your supplier quotes.
A finished driveway usually has a 4–6 in compacted base of 1.5–3 in crushed stone under a 2–3 in top layer of 3/4 in gravel. Paths and patios use 2–3 in over compacted soil. Calculate each layer separately at its own depth.
Multiply length by width in feet, multiply by the depth in feet (inches ÷ 12), then divide by 27. Add 10% for compaction and uneven ground. A 20 × 10 ft area at 3 in is 50 ÷ 27 = 1.85 yd³ before allowance.
One ton of typical crushed stone is about 0.71 cubic yards, or 19 cubic feet. At 3 inches deep it covers about 77 sq ft; at 2 inches about 116 sq ft. Coverage falls as depth or density rises.