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This gravel calculator works out how much gravel, crushed stone, pea gravel, river rock or sand you need for a driveway, path, patio base or drainage area. It converts your measurements into volume and weight, so you can order by the cubic yard, the ton, the cubic meter or the tonne.
How to Use the Gravel Calculator
- Pick the material. Each option uses a typical density, because suppliers sell most aggregates by weight.
- Enter the length and width of the area to cover.
- Enter the depth of the layer. Paths often use 2–3 in (5–8 cm), driveways 4–6 in (10–15 cm) or more.
- Add extra for compaction. Gravel and crushed stone settle when they are compacted, so 10–15% is common.
- Optionally enter the price per ton or tonne to estimate the cost.
Gravel Formula
Volume = Length × Width × Depth
Weight = Volume × Density
In the US, divide cubic feet by 27 for cubic yards, then multiply by the density in tons per cubic yard. General gravel is about 1.4 tons per cubic yard (around 1,680 kg/m³). In metric, multiply cubic meters by the density in tonnes per cubic meter.
Worked Example: 20 × 10 ft Path, 3 Inches Deep
- Depth: 3 in ÷ 12 = 0.25 ft
- Volume: 20 × 10 × 0.25 = 50 cu ft = 1.85 cubic yards
- Weight: 1.85 yd³ × about 1.42 tons per yd³ = 2.62 tons
- With 10% extra for compaction: about 2.9 tons
Metric example: a 6 × 3 m parking area 10 cm deep holds 1.8 m³. At 1.68 t/m³ that is about 3.0 tonnes, or 3.3 tonnes with 10% for compaction.
Typical Densities of Common Aggregates
| Material | kg per m³ | Tons per cubic yard | Common uses |
|---|---|---|---|
| Gravel (general) | ≈1,680 | ≈1.42 | Driveways, bases |
| Crushed stone | ≈1,600 | ≈1.35 | Sub-base, drainage |
| Pea gravel | ≈1,550 | ≈1.31 | Paths, play areas, patios |
| River rock | ≈1,500 | ≈1.26 | Decorative beds, drainage |
| Sand | ≈1,600 | ≈1.35 | Paver bedding, leveling |
Densities change with moisture and stone size, so suppliers’ own figures may differ by 10% or more. If your supplier lists a different density, use it to fine-tune the estimate.
Recommended Gravel Depths
- Garden paths: 2–3 in (5–8 cm) of pea gravel or decorative stone over a weed membrane.
- Patio or paver base: 4–6 in (10–15 cm) of compacted crushed stone, plus about 1 in (2.5 cm) of sand.
- Driveways: 4–8 in (10–20 cm) in layers, with larger stone at the bottom and finer stone on top.
- Drainage trenches: fill the trench depth with clean, washed stone.
Tips for Buying Gravel
- Bulk delivery is usually far cheaper than bags once you need more than about half a ton.
- Ask whether the price is per ton, per cubic yard or per bulk bag. A UK bulk bag typically holds about 850 kg.
- Install and compact base layers in lifts of 2–3 in (5–8 cm) for a firm, long-lasting surface.
- Topping beds with mulch or soil instead? Use our mulch and topsoil calculator.
Frequently Asked Questions
How much does a cubic yard of gravel weigh?
A cubic yard of typical gravel weighs about 2,800 lb, or roughly 1.4 US tons. Crushed stone and pea gravel are a little lighter, and wet material is heavier.
How many tons of gravel do I need for a driveway?
Multiply length × width × depth to get the volume, then multiply by about 1.4 tons per cubic yard. A 50 × 12 ft driveway with 4 inches of gravel needs about 7.4 cubic yards, or roughly 10.4 tons.
How much area does a ton of gravel cover?
At 2 inches deep, one ton of gravel covers roughly 115–120 sq ft. At 3 inches it covers about 75–80 sq ft and at 4 inches about 55–60 sq ft.
Why add extra for compaction?
Loose gravel compresses when it is rolled or tamped, and some works into the soil below. Adding 10–15% makes sure you reach the finished depth you want.
Can I use this for sand or crushed stone?
Yes. Choose sand or crushed stone from the material list and the calculator will use a typical density for that material.
Related guide: How Much Gravel Do I Need for a Driveway?
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