Gravel and Aggregate Calculator

Gravel and Aggregate Calculator

How much gravel, crushed stone, sand or soil a job takes, in volume and in weight: because suppliers sell some materials by the cubic yard and others by the ton, and the bridge between the two is the material’s bulk density, which this page shows and lets you change. It covers rectangles, circles and triangles, adds an allowance for compaction and waste, and works out bags, truck loads and cost when you give it prices.

Buying (optional)

Disclaimer: This calculator gives estimates for general information only. It is not financial, medical or other professional advice. Bulk densities vary with stone type, grading and moisture; the figures pre-filled here are typical values, and your supplier’s own density for the material you are buying governs the weight you will actually receive.

What this calculator does

Loose materials live in two currencies at once: space and weight. A driveway needs a volume of gravel, but the yard may sell it by the ton, the truck is limited by tons, and the bags are labelled in pounds. This calculator works the whole chain: area times depth gives the volume in place, a compaction and waste allowance turns it into an order volume, and the material’s bulk density, shown and editable, turns volume into weight: pounds, US tons and metric tonnes. It then answers the buying questions: how many bags at the weight you set, how many truck loads at your truck’s capacity, and what it costs at a price per ton or per cubic yard. A coverage line runs the maths backwards: how much ground one ton covers at your depth, the figure for sanity-checking a yard’s advice.

How to use it

  1. Depth is the decision, not a detail. Common depths: 2 to 3 inches for a gravel driveway top-up over a sound base, 4 inches for a new driveway layer, 1 to 2 inches for decorative stone and paths, 3 to 4 inches for a shed or slab base. Enter the compacted depth you want to finish with; the extra allowance then covers the fact that loose material settles into less than its delivered depth.
  2. Density is an assumption with a name on it. Pick the material and the field fills with its typical bulk density: gravel at 105 lb per cubic foot, crushed stone and sand at 100, topsoil at 85. Real densities move with stone type, grading and, above all, moisture: wet sand can weigh a tenth more than dry. If your supplier quotes a density or a tons-per-yard figure for their material, type it in; it outranks the defaults, and the page says so in the disclaimer rather than hiding it.
  3. The extra allowance does two jobs. Loose aggregate compacts roughly 10% when it is spread and rolled, and irregular edges and spillage eat a little more. Ten percent is the honest default for most jobs. Ordering the in-place volume exactly is how a project ends up one thin corner short on a Saturday afternoon.
  4. Tons and yards are both printed because yards (the suppliers) cannot agree. Some sell by the cubic yard, some by the ton, and the conversion between them is the density on this page, not a universal constant. If a supplier tells you “a yard is about a ton and a half”, that is their density talking: 1.5 tons per yard means about 111 lb per cubic foot, and you can type it straight into the density field.
  5. Bags are the expensive way to buy bulk. The bag count is provided because small jobs are real, but read the count when it appears: 154 fifty-pound bags for a modest driveway area is the calculator suggesting, politely, that a bulk delivery exists. The truck-load line assumes the capacity you enter; leave it empty if a supplier’s truck is doing the driving.

How it is calculated

Area: rectangle = length x width; circle = pi x (diameter/2) squared; triangle = base x height / 2. Volume in place = area x depth. Order volume = volume in place x (1 + extra/100). Weight = order volume in cubic feet x bulk density in lb per cubic foot. US tons = pounds / 2,000. Metric tonnes = pounds x 0.00045359237. Conversions: 1 cubic yard = 27 cubic feet; 1 cubic metre = 35.3147 cubic feet; a density of 1 lb per cubic foot equals 16.0185 kg per cubic metre. Bags = weight / bag weight, rounded up. Truck loads = tons / capacity, rounded up. Coverage per ton = (2,000 / density) / depth in feet.

Worked examples

The driveway top-up: 20 ft by 10 ft at 4 inches of gravel, density 105, with the 10% extra. Volume in place 66.67 cubic feet (2.47 cubic yards); order volume 73.33 cubic feet, 2.72 cubic yards; weight 7,700 lb, 3.85 US tons (3.49 metric tonnes). The coverage line reads 57.14 square feet per ton at that depth: at 200 square feet, the yard’s “about four tons” checks out.

The round bed: a 12 ft diameter circle, 3 inches of crushed stone at density 100, no extra: 113.10 square feet, 28.27 cubic feet, 1.05 cubic yards, 2,827 lb, 1.41 tons.

The triangle: a corner bed, base 10 ft, height 8 ft, 6 inches of sand: 40 square feet, 20.00 cubic feet, 0.74 cubic yards, exactly 1.00 ton at density 100, a reminder that triangles hold half of what their bounding rectangle suggests.

The metric job: 5 m by 4 m at 10 cm of gravel: 2.00 cubic metres (70.63 cubic feet, 2.62 cubic yards), weighing 7,416 lb, 3.71 US tons, 3.36 metric tonnes. The density field in metric reads 1,682 kg per cubic metre, the same gravel wearing metric clothes.

Bags and trucks, from the driveway: 3.85 tons is one load in a 5-ton truck, and 154 bags of 50 lb: the two buying methods priced side by side, which is usually the end of the bags idea for anything driveway-sized.

Reading your result

Order on weight when the supplier sells on weight and on the order volume when they sell by volume, and notice they are the same pile: the density you chose is the only thing translating between the two quotes, so if two suppliers’ quotes differ wildly per ton versus per yard, the density field is where the disagreement lives. Keep the in-place and order volumes separate in your head: the in-place figure is what the finished job contains, the order figure is what leaves the yard, and the difference is compaction you already paid to lose. If a delivery arrives and the pile looks small, spread it before you argue: a compacted 4 inches over 200 square feet is a smaller-looking pile than most people picture, and this page’s coverage line is the neutral referee.

Limitations

  • Density is typical, not certified. The single largest error source in this whole calculation is the density. Stone type, the mix of sizes in the grading, and moisture all move it, and no calculator can weigh your supplier’s pile from a web page. The defaults here are the published typical values for each class; a supplier’s own figure always wins.
  • Depths assume a level base. Volume equals area times depth only when the surface underneath is roughly flat. A rutted driveway being topped up takes material in proportion to its ruts; add extra, or grade first and measure after.
  • Compaction varies with material and method. Angular crushed stone locks and settles differently from round pea gravel, which barely compacts at all and migrates instead. Ten percent is a working default, not a property of nature.
  • Delivery minimums and fees sit outside the maths. Many yards have a minimum load, a delivery fee by distance, and sometimes a fuel surcharge. Cost lines here are marked “before delivery” because that is the truth of them.

Frequently asked questions

How much gravel do I need for a driveway?

Multiply the driveway’s length by its width for the area, choose the finished depth (4 inches for a new layer, 2 to 3 for a top-up), and the volume is area times depth: a 20 by 10 driveway at 4 inches is 66.67 cubic feet, 2.47 cubic yards in place, about 2.72 yards and 3.85 tons to order with a 10% allowance at gravel’s typical density. This page then prices it both ways, by the ton and by the yard, because suppliers quote both ways.

How many tons are in a cubic yard of gravel?

At the typical density used here, 105 lb per cubic foot, a cubic yard weighs 2,835 lb, about 1.42 US tons. Crushed stone at 100 gives about 1.35 tons per yard, which is where the yardman’s “about a ton and a third” comes from, and topsoil is lighter at about 1.15. The honest answer is always density times 27 divided by 2,000, and this page shows its density so you can argue with it.

Why order more than the exact volume?

Because loose stone does not stay loose. Spread and compacted, a pile loses roughly a tenth of its depth to settling into the base and itself, and edges, spillage and the thin spots in a hand-spread layer take a little more. Running short means a second delivery, a second delivery fee, and a visible seam where the loads meet; running slightly long means a small pile left for touching up ruts, which gravel driveways always need eventually.

Is it cheaper to buy bags or bulk?

Bulk, almost always, once the job passes a few hundred pounds: bagged material commonly costs several times the per-ton price of the same stone loose, and the bag count line in the results tends to make the case by itself. Bags earn their place on genuinely small jobs, a single post hole’s worth of stone, a path repair, anywhere a delivery fee would swamp the material cost, and anywhere a truck cannot reach.

Related calculators

Method: area by shape as defined on this page, volume = area x depth, order volume with the user’s compaction and waste allowance, weight = volume x user-visible bulk density. Typical densities pre-filled by material class (gravel 105, crushed stone 100, pea gravel 100, river rock 105, sand 100, topsoil 85, decomposed granite 95, riprap 110 lb per cubic foot) and fully editable. Last reviewed: 13 October 2026.