Gravel Calculator

How much gravel do I need?

Work out the volume first: area × depth. A 200-square-foot path 3 inches deep holds 200 × 0.25 = 50 cubic feet, or about 1.85 cubic yards. Because quarries and landscape suppliers often sell gravel by weight, the calculator then multiplies the volume by the material's density. Loose gravel weighs roughly 1,600 kg per cubic meter (about 100 lb per cubic foot), so the same path needs about 2.5 short tons. Sand mixed with gravel, or wet sand, is noticeably heavier per yard.

Typical depths are 2 to 3 inches for a decorative or walking surface and 4 to 6 inches or more for a driveway, usually laid in layers over a compacted base of larger crushed stone. Compaction reduces volume, so order 5 to 10 percent extra for base layers. If a supplier quotes per ton and you know the cubic yards, a common rule is about 1.4 tons per cubic yard for gravel, but check the supplier's own figure.

What is gravel used for?

Gravel is one of the most widely used construction materials. Crushed stone and gravel are the main aggregates in concrete and asphalt, making up most of their volume, and they form the base layers beneath roads, sidewalks, building slabs and railway tracks, where they spread loads and drain water away. Railway ballast, the bed of angular crushed stone under the ties, holds track in place and lets rain drain quickly.

Around the home, gravel makes inexpensive, permeable driveways and paths that let rainwater soak into the ground rather than run off. It is used as a base for patios, pavers and sheds, as backfill around foundation walls and in French drains that carry water away from a house, and as mulch in dry gardens and around succulents. Pea gravel is a common surface under playground equipment and in dog runs. Gravel also filters water in septic drain fields, and it lines the bottom of ponds, aquariums and planters.

Choosing the right stone matters. Angular crushed stone locks together when compacted and stays put on driveways and bases, while rounded stones like pea gravel and river rock roll underfoot and are better for decorative areas and drainage. Edging along paths and beds keeps gravel from spreading into lawns.

Types of gravel

Gravel is classified by size, shape and origin. Geologists define gravel as rock fragments from about 2 mm up to 64 mm across; larger pieces are cobbles and boulders, and smaller grains are sand. Commercially, crushed stone is made by quarrying and crushing bedrock such as limestone, granite or trap rock, while natural gravel is dug from riverbeds and glacial deposits and is usually rounded.

Suppliers sell many graded products. Crushed stone is screened into sizes, often identified in the US by numbers such as #57 (roughly ¾ to 1 inch) or #411, a blend of stone and fines that compacts well. Dense-graded aggregate, sometimes called crusher run, road base or quarry process, mixes stone with fine dust so that it packs into a hard, stable layer. Washed stone has the fines removed, so it drains freely. Names and gradations vary by region, so describe your project to the supplier.

Frequently asked questions