Gravel Driveway Calculator
Works out the gravel for a driveway. This covers the gravel layer only — a drive that carries vehicles also needs a compacted sub-base underneath, which is a separate material and a separate order.
Includes the waste allowance — this is the figure to order.
Share sends a link that reopens these numbers. Copy details pastes the full breakdown as a list.
The formula
volume = length × width × depth × (1 + waste) weight = volume × bulk density
The geometry is trivial; the bulk density is where the answer actually comes from. Gravel runs about 1550 kg per cubic metre loose, so a cubic metre weighs roughly 1.55 tonnes. Suppliers quote one or the other, which is why both are given.
What to watch out for
A gravel drive is two layers, and people routinely order only one:
- Sub-base, 100–150 mm compacted. Crushed stone or MOT Type 1, whacked down in layers. This is the structural part — it spreads the wheel load and stops ruts.
- Gravel, 50 mm. The surface you see. Deeper is not better: above about 60 mm, tyres push through it and it migrates to the edges.
Edging matters as much as depth. Without a kerb, timber or a hard edge, gravel ends up in the lawn and on the road within a season.
Frequently Asked Questions
How much gravel for a driveway?
A 10 × 3 m drive at 50 mm needs about 1.5 m³ of gravel, roughly 2.6 tonnes with waste. Add the sub-base separately — at 150 mm that is another 4.5 m³ of crushed stone.
How deep should a gravel driveway be?
50 mm of gravel over 100–150 mm of compacted sub-base. The temptation is to skip the sub-base and lay 150 mm of gravel instead, which produces a drive that ruts immediately and is unpleasant to walk on.
What size gravel is best for a driveway?
10–20 mm angular stone. Angular pieces lock together and stay put; rounded pea gravel rolls under tyres and migrates. Anything under 10 mm gets carried away in tyre treads.