Gravel Calculator

Stone is measured by volume on site but often sold by weight at the quarry or landscape yard. This calculator works out the volume from your measurements, then uses a bulk density to estimate the weight, so you can compare prices quoted per cubic yard, per cubic metre, per US ton or per tonne.

The material list includes common choices such as crushed stone, pea gravel, river rock, decomposed granite and road base (sold as crusher run in the US and MOT Type 1 sub-base in the UK). Each comes with a typical density that you can replace with your supplier’s number.

1. Measure the length and width of the area to be covered.
2. Enter the finished depth of stone. For layered builds, calculate each layer separately.
3. Set an extra allowance for compaction and spreading losses. Compactable materials such as road base settle when rolled.
4. Choose the material. The density field fills in automatically; overwrite it if your supplier gives a different figure.
5. Optionally add a price per ton, tonne, cubic yard or cubic metre.

Volume = Length × Width × Depth

Volume to order = Volume × (1 + Extra % ÷ 100)

Weight = Volume to order × Density

Density is expressed per unit of volume, for example 1.35 US tons per cubic yard, 100 lb per cubic foot or 1.6 tonnes per cubic metre. Keep US short tons (2,000 lb, 907.2 kg) and metric tonnes (1,000 kg) separate. A “ton” quoted in the US is usually a short ton, while UK, Canadian and Australian suppliers quote tonnes.

A driveway 40 ft long, 10 ft wide, with 4 inches of crushed stone:

• Volume: 40 × 10 × (4 ÷ 12) = 133.3 cubic feet = 4.94 cubic yards
• With 5% extra: 140 cubic feet = 5.19 cubic yards (3.96 m³)
• At an assumed 1,600 kg/m³ (about 1.35 US tons per cubic yard): roughly 7.0 US tons, or 6.3 tonnes

In metric, a 12 m × 3 m area at 100 mm deep is 3.6 m³, or 3.78 m³ with 5% extra, which is around 6.0 tonnes at the same density.

• Gravel needed – volume including your extra allowance, in cubic yards or cubic metres.
• Net volume – the geometric volume of the space before any allowance.
• Estimated weight – volume × density. Shown in US short tons, metric tonnes, pounds and kilograms. Treat it as an estimate, not a guaranteed purchase quantity.
• Estimated cost – based on whichever price unit you choose.

• Decorative paths are often laid 2–3 inches (50–75 mm) deep. Driveways normally need a thicker, compacted base of coarse stone with a finer surface layer; follow local guidance for your soil and traffic.
• Excavate and compact the soil first, and consider a landscape fabric to separate stone from soil.
• Edging keeps gravel from migrating into lawns and beds, which reduces top-ups.
• Ask whether the supplier’s price includes delivery and what the minimum load is.

• Moisture – wet stone and sand weigh noticeably more than dry material.
• Grading – mixes with fines (road base, crusher run) pack more tightly than single-size stone.
• Compaction – compacted road base occupies less volume than it did loose in the truck.
• Rock type – limestone, granite and basalt have different densities.

For paver patios, the paver calculator includes base and bedding sand volumes. For mulch or soil instead of stone, use the mulch calculator. Our guide to calculating gravel for a driveway covers layering in more detail.