Gravel Calculator
Cubic yards and tons of gravel, crushed stone, sand or asphalt for an area and a depth, with the 10% you lose to compaction and the cost per ton.
Order
8.8 tons
5.93 yd³ compacted · 8 tons before the 10% allowance
- Area
- 480 ft²
- Volume
- 5.93 yd³
- Cubic feet
- 160 ft³
- Tonsshort tons of 2,000 lb
- 8
- Order with 10% compaction
- 8.8 tons
- Costorder × price per ton
- 281.60
Kalku is coming to iPhone and Android
The app has this calc and the rest of the paving and groundwork ones: gravel under a slab, sand beds, pavers, asphalt, excavation and backfill with swell and shrinkage for each soil type. It draws the layer in 3D, turns cubic yards into tons with one key on its keypad, and works with no signal on site.
From volume to tons
Gravel is quoted by the ton but spread by volume, so the calculation has two halves. The volume is length × width × depth. The weight is that volume times the density of the material, and that is where the uncertainty is: a cubic foot of gravel or crushed stone weighs about 100 lb, sand about the same, compacted asphalt about 145. Those are the figures the Kalku app works with, and the density field is there so you can use your supplier's.
The order figure adds 10% to the tons. Loose stone settles when it is compacted, and the ground under it is never dug exactly to depth, so ordering the bare volume reliably leaves you short. The cost is the order times your price per ton.
Worked example: a 40 × 12 ft drive, 4 inches deep
- Area: 40 ft × 12 ft = 480 ft².
- Volume: 480 ft² × 4/12 ft = 160 ft³, which is 160 ÷ 27 = 5.93 yd³.
- Weight: 160 ft³ × 100 lb = 16,000 lb = 8 short tons.
- Order with 10% for compaction: 8.8 tons; at 32 a ton, 281.60.
The same job in metric is 4.53 m³ and 7.26 tonnes, 7.98 with the allowance: the tonne is heavier than the short ton, so there are fewer of them.
Driveways, paths and bases
Most gravel jobs are layers: a coarser compacted base and a finer top, or a stone base under a slab, pavers or a shed. Work each layer out on its own with its own depth and density. Mulch, topsoil and compost are sold by volume rather than weight; for those, use the mulch calculator, which counts bags.
Questions
How much does a cubic yard of gravel weigh?
At the calculator's default of 100 lb per cubic foot, a cubic yard (27 cubic feet) weighs 2,700 lb, about 1.35 short tons. Real gravel varies with the stone and how wet it is: crushed stone runs about 95 to 110 lb per cubic foot loose. If your supplier quotes a weight per yard, divide it by 27 and use that as the density.
How many tons of gravel do I need for my driveway?
Multiply the length, width and depth for the volume, multiply by the density for the weight, and add 10% for compaction. A 40 by 12 foot drive at 4 inches is 160 cubic feet: 8 tons, so order 8.8. How deep a driveway's layers should be depends on the ground and the traffic, so ask your supplier or follow local practice.
Why add 10% for compaction?
Gravel is delivered loose and shrinks when it is compacted, and a sub-base is never dug to a perfect depth. The calculator adds 10% to the tonnage, as the Kalku app does. Crushed stone under a slab is often allowed 10 to 20%; the app's Gravel Under Slab calc lets you set the allowance yourself.
Tons or tonnes?
In feet and inches the calculator uses US short tons of 2,000 lb. In metric it switches to metric tonnes of 1,000 kg, which are about 10% heavier, and the price is per tonne. A quote in one cannot be compared with a figure in the other without converting.
