Enter your area length, width and depth to get the gravel volume in cubic yards or cubic metres - plus how many bags to buy. Ideal for driveways, paths, pea gravel and drainage. Works in feet/inches or metres/centimetres.
Typical depths: 50–75 mm (2–3 in) for mulch, 40–50 mm for decorative gravel, 100 mm (4 in)+ for new topsoil, deeper again to fill a raised bed. Each area can take its own depth.
Total bed area
10.0 sq ft
In cubic feet
4.2 cu ft
Gravel is spread to an even depth, so the amount you need is the area times the depth:
volume = length × width × depth
The calculator reports that volume in cubic yards or cubic metres (and litres or cubic feet), then divides by the size of one bag to give the number of bags. Covering a driveway plus a separate path? Add an area for each and the volumes pool into one order. All math runs in exact metric internally, so switching units never changes the answer.
A 10 m × 3 m driveway at 100 mm deep, ordered in bulk:
In US units, a 30 ft × 10 ft driveway at 4 inches deep is 300 sq ft × (4 ÷ 12) = 100 cu ft ≈ 3.7 cubic yards.
| Job | Depth | Notes |
|---|---|---|
| Decorative / pea gravel | 40–50 mm (1.5–2 in) | Over a weed membrane |
| Path or patio top layer | 50 mm (2 in) | Over a compacted base |
| Driveway (gravel layer) | 100–150 mm (4–6 in) | Over a separate sub-base |
| French drain | full trench depth | Around the drainage pipe |
Multiply the driveway area by the depth. A 10 m × 3 m driveway at 100 mm deep needs 3 m³ of gravel; a 30 ft × 10 ft driveway at 4 inches deep is about 3.7 cubic yards. Enter your exact size and depth above. For a new driveway also allow a separate sub-base layer underneath.
Use 40–50 mm (1.5–2 in) for a decorative gravel layer over a membrane, and 100–150 mm (4–6 in) of gravel for a driveway that takes vehicles, laid over a compacted sub-base. For a French drain, fill the trench depth around the pipe. Set your depth in the calculator to match the job.
Gravel is heavy - roughly 1.4–1.7 tonnes per cubic metre, or about 1.2–1.5 US tons per cubic yard, depending on the stone and moisture. Bulk gravel is often sold by weight (tonnes) as well as volume, so once you have the volume from the calculator, ask the supplier for the weight per cubic yard or tonne.
A standard 0.5 cubic foot bag of pea gravel covers about 3 sq ft at 2 inches deep; a 50-litre bag covers about 1 m² at 50 mm deep. Pea gravel is the small rounded stone often used for paths and borders. Enter your area and depth above and the calculator returns the bag count for you.
Bags suit small jobs - a border, a few square metres of path - and are easy to carry. For a driveway or any large area, bulk delivery by the cubic yard or tonne is far cheaper per unit, but you need somewhere to tip it and a barrow to move it. The calculator gives both a bag count and a bulk volume so you can compare.
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