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Gravel Calculator: How Many Tonnes of Stone Do You Need?

Enter the area and depth for a driveway, slab base or patio. You get cubic metres, cubic yards and an order in tonnes.

Short version: Volume = length × width × depth. Add 10-20% for compaction and waste, then multiply by the stone density (about 1.5 to 1.7 tonnes per cubic metre) to get the tonnes to order.

Calculate your gravel

How the calculator works

  • Granular base compacts, so order extra: 10 to 20% is common.
  • Densities are typical planning values; quarries quote their own.
  • Under a slab or driveway, the depth comes from your drawings or contractor.

Pouring concrete on it? Use the concrete calculator and the rebar calculator.

Questions people ask

How much gravel do I need for a 24 x 24 area?

At 6 inches deep with 15% for compaction, about 9.4 m³, or roughly 15 tonnes of crushed stone. Use the calculator for your exact numbers.

How many tonnes are in a cubic metre of gravel?

About 1.5 to 1.7 tonnes for most crushed stone, clear stone and screenings. Ask your supplier for their figure.

How deep should gravel be under a driveway?

It depends on soil and use; your contractor or township standard sets it. Many residential driveways use several inches of granular base.

Related guides on BuildersOntario

Concrete calculatorCubic metres, trucks and costRebar calculatorBars, metres and weightLot grading and drainageOntario rules for new homesDriveway entrance and culvert permitsBefore you build the driveway

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Updated November 2026. Quantities are estimates; confirm depth and material with your contractor and supplier.