Gravel calculator: tons, cubic yards and m³
This gravel calculator works out how much gravel, crushed stone, sand or topsoil you need for a driveway, garden path, French drain, shed base or decorative bed. Enter the shape and size of the area and the depth, and it gives the volume in cubic metres, cubic yards and cubic feet, the weight in tonnes and US tons, the number of bags, and the Indian brass (100 ft³) that aggregate is often sold in.
Suppliers price stone by weight or by volume, and the link between the two is the material’s density. The calculator uses loose bulk densities from Caterpillar’s published earthwork reference tables — for example 1,600 kg/m³ (2,700 lb/yd³) for crushed stone — and lets you type your supplier’s own figure instead.
Add an allowance for compaction and waste, enter a price per tonne, cubic yard or brass if you like, and copy the summary for your order. Everything runs in your browser.
How to use the Gravel Calculator
- Choose metric or imperial units and the shape of the area: rectangle, circle, triangle, or an area you already know.
- Enter the dimensions and the depth of gravel (mm or inches).
- Pick the material; the loose density fills in automatically. Overwrite it if your supplier gives a different figure.
- Set the extra for compaction and waste — 10% is a sensible start, 15–20% for a compacted driveway base.
- Optionally choose a bag size and enter a price per tonne, m³, cubic yard, US ton or brass, then read the result and copy the summary.
Gravel Calculator features
Every unit people order in
Tonnes, US tons, m³, cubic yards, cubic feet and brass side by side.
Material presets
Gravel, coarse gravel, crushed stone, dry sand and topsoil with published loose densities.
Four shapes
Rectangles, circles and triangles, or type the area directly for odd shapes measured elsewhere.
Bags or bulk
20 kg, 25 kg, 50 lb and 0.5 ft³ bags, or roughly 850 kg bulk bags.
Cost estimate
Price per tonne, m³, cubic yard, US ton or brass in your currency.
How the gravel calculation works
Volume = area × depth. Add the compaction and waste allowance, then weight = volume × density. Example: a driveway 10 m × 3 m covered 100 mm deep needs 3 m³ of gravel. At 1,510 kg/m³ that is 4.53 tonnes — 3.92 cubic yards, 106 ft³ or 1.06 brass. With 10% extra it becomes 3.3 m³ and 4.98 t.
In imperial units: 20 ft × 10 ft × 4 in = 66.7 ft³ = 2.47 cubic yards. At 2,550 lb per cubic yard that is 6,296 lb, or 3.15 US tons. A quick rule of thumb many yards use is about 1.4 tons per cubic yard for gravel; the calculator uses the density you choose instead.
Typical loose densities
Values are loose (as delivered) densities from Caterpillar’s earthwork reference tables. Wet material is heavier; ask your quarry for its figure when buying by weight.
| Material | kg/m³ | lb/yd³ | Tons per yd³ |
|---|---|---|---|
| Gravel, dry | 1,510 | 2,550 | 1.28 |
| Gravel, ¼–2 in (6–50 mm) | 1,690 | 2,850 | 1.43 |
| Crushed stone | 1,600 | 2,700 | 1.35 |
| Sand, dry | 1,420 | 2,400 | 1.20 |
| Topsoil | 950 | 1,600 | 0.80 |
Depth and ordering tips
- Driveways: 100–150 mm (4–6 in) of crushed stone in two or three compacted layers, coarse at the bottom. Compaction reduces the loose volume, so order extra.
- Paths and patios: 50–75 mm (2–3 in) over a weed membrane. Decorative gravel: about 40–50 mm (1½–2 in).
- One brass is 100 ft³ (2.83 m³), the usual unit for sand and aggregate in India; tipper loads are often 2–4 brass.
- Digging out first? Work out the spoil and truckloads with the excavation calculator. Pouring a slab on the base? Use the concrete calculator. For irregular areas, measure with the area calculator and choose “I know the area”.
Gravel Calculator FAQ
How many tons of gravel do I need for a driveway?
Multiply length × width × depth to get the volume, then multiply by the density. A 12 × 3 m driveway 150 mm deep is 5.4 m³, about 8.6 tonnes of crushed stone at 1,600 kg/m³. The gravel calculator does the conversion and adds compaction.
How many cubic yards of gravel do I need?
Square feet × depth in inches ÷ 324 gives cubic yards. A 20 × 10 ft area 4 in deep is 200 × 4 ÷ 324 = 2.47 cubic yards.
How much does a cubic yard of gravel weigh?
Roughly 2,500–2,900 lb (1.25–1.45 US tons) when dry and loose, depending on stone size. Crushed stone is about 2,700 lb per cubic yard.
How do I convert tons of stone to m³?
Divide the weight in kilograms by the density. 10 tonnes of crushed stone at 1,600 kg/m³ is 10,000 ÷ 1,600 = 6.25 m³.
What is a brass of aggregate?
A brass is 100 cubic feet, or 2.83 m³. It is the unit used for sand, gravel and aggregate in much of India. At 1,600 kg/m³ one brass of aggregate weighs about 4.5 tonnes.
Why should I add extra gravel?
Gravel settles and compacts, the ground is never perfectly level, and some is lost at the edges. 10% covers most loose jobs; compacted driveway bases often need 15–20% more than the finished volume.