Aggregate Calculator
Work out graded base aggregate — crusher run, road base, clean crushed stone — in tons and cubic yards by the material's own density.
Base rock is a density business
Aggregate for bases is graded material — stone in every size down to dust — so it compacts into a near-solid mat, and weighs more per yard than clean stone or loose gravel. Crusher run runs about 1.5 tons per cubic yard; clean #57 drainage stone, with air in it, about 1.35. This calculator answers in the two units aggregate is sold in — tons at the scale house, cubic yards by volume — using the density of the type you choose.
Tons = area × depth ÷ 27 × tons per cu yd for the material
Example: a 20 × 10 ft driveway base, 4 in of crusher run, is 2.47 cu yd exactly — 4.07 tons with the 10% allowance in, before compaction settles it.
Loose, delivered, compacted
The depth you enter should be the compacted depth you want under the finished surface — that is the honest basis, and the waste allowance covers the difference between the loose pile that arrives and the mat it becomes (roughly 10–15% shrinkage under a plate compactor or roller). Lay deep bases in two lifts and compact each; a single 6 in lift compacts at the top and stays soft underneath, and the surface above it will find that out.
Graded versus clean is a drainage decision, not a price one: crusher run and road base lock up hard and shed water slowly; #57 and other clean stone pass water freely and belong behind retaining walls, under French drains and anywhere the base must not hold moisture against a foundation.
Frequently asked questions
What is the difference between crusher run and gravel?
Gravel is rounded and mostly one size — it rolls under load. Crusher run is angular and graded from dust to 3/4 in, so it knits together under compaction into a slab-like base. For driveways and under slabs, the graded material is the professional choice; the densities here reflect that.
How thick should a driveway base be?
4 in compacted is the minimum over decent soil for cars; 6 in over clay or soft ground, and 8 in or more where trucks park. Poor soil, not traffic, is what usually decides — dig a test hole before ordering.
Tons or cubic yards — how will I be charged?
Most quarries and yards weigh the truck and charge by the ton; some sell by the yard from a loader bucket. The result gives both so you can compare quotes honestly — convert with the material's density, never 1:1.
Should I order extra for compaction?
The figures here are for the compacted depth you enter, and the 10% allowance roughly covers loose-to-compacted shrinkage. On soft ground where the first lift sinks in, order to the allowance and keep the supplier's number for a top-up load.
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