Gravel Calculator

Enter the size of the area and the depth of gravel you want, and this calculator works out the volume in cubic yards, cubic feet and cubic meters and the weight in tons, so you can order the right amount. It handles rectangles, circles and triangles, metric or imperial measurements, an allowance for compaction and waste, and an optional price per ton for a cost estimate. A chart compares the tonnage at common depths.

volume (yd³) = length (ft) × width (ft) × depth (in) ÷ 12 ÷ 27

weight (tons) = volume (yd³) × tons per cubic yard

Dividing by 12 converts inches to feet, and dividing by 27 converts cubic feet to cubic yards. A circle uses π × (diameter ÷ 2)² for the area, and a triangle uses base × height ÷ 2. One cubic yard is 0.7646 cubic meters.

A driveway 40 by 10 feet, 4 inches deep, needs 5.43 cubic yards including a 10% allowance, about 7.6 tons at 1.4 tons per cubic yard.

A round patio base 12 feet across, 4 inches deep, needs 1.40 cubic yards, about 1.95 tons.

Gravel is sold by volume or by weight, so the conversion matters. The weight of a cubic yard depends on the type of stone, the size and shape of the pieces, how much moisture they hold and how tightly they are packed. Supplier figures for crushed stone commonly fall around 1.3 to 1.7 short tons per cubic yard, and the calculator starts at 1.4 as a typical value. Ask your supplier for the figure they use for the exact product, which they measure with a standard method such as ASTM C29, and enter it for the most accurate order.

Angular crushed stone locks together when compacted, which makes it the usual choice for driveway and patio bases. Rounded pea gravel is comfortable underfoot and drains well, so it suits paths and play areas, but it shifts more and needs edging to stay in place. Stone with fine particles mixed in, often sold as crusher run or road base, packs into a firm surface. The type affects the weight per cubic yard, so check the figure for the product you choose.

• Add 5 to 10% for compaction, uneven ground and spillage, more for a base layer you will compact heavily.
• Most suppliers deliver in whole or half tons or yards, and many have a minimum delivery, so round up.
• For several areas, run each one and add the results.
• Bagged gravel is convenient for small jobs; for more than about a cubic yard, bulk delivery is usually cheaper.

For mulch, topsoil or compost in garden beds, the mulch calculator works in cubic yards and bags. For a concrete slab, footing or post holes, the concrete calculator includes bags of premix and ready-mix volume. Gravel is also used under concrete as a base, so you may need both.