Stone Dust Density

Stone dust — also sold as screenings, crusher dust, quarry dust or stone screenings depending on where you are — is the fine material left over when rock is crushed. Because the particles are small and angular, it packs far tighter than clean stone, and that single property drives everything about how you order it.

Stone Dust Density Chart

These are typical values. Actual density depends on the parent rock — dust crushed from granite or trap rock is heavier than dust from limestone — so a quarry in one region can be 10% off a quarry in another. Ask your supplier for their figure if you are ordering by the truckload.

Stone Dust Unit Weight in kg/m³, kN/m³ and per CFT

Unit weight and density describe the same property — civil engineering drawings and textbooks tend to say unit weight, suppliers say density, and they are interchangeable in practice. The only real distinction is the unit: density is usually written in kg/m³, while structural calculations often want kN/m³, which is simply the density multiplied by gravity (9.81) and divided by 1,000.

These are the same figures as the chart above, converted rather than re-measured — 1 lb/ft³ is 16.018 kg/m³. The CFT column matters if you are buying in India or elsewhere in South Asia, where material is ordered by cubic feet but billed by the tonne. One tonne of loose stone dust occupies roughly 21 CFT, so 100 CFT — one brass — comes to about 4.7 tonnes. Our ton to CFT stone calculator does that conversion in either direction.

One naming note that causes real confusion: quarry dust, crusher dust, crusher run fines, screenings and stone dust are broadly the same product under regional names. Where they genuinely differ is fineness and parent rock, not category — so the density figures above apply to all of them, and any spread you see between two suppliers is down to the rock and the moisture rather than the label on the invoice.

Why Compacted Density Is the Number That Matters

Stone dust is bought loose and installed compacted. That gap is the single most common reason people run short. A plate compactor drives the fine particles into the voids between the larger ones, and the same material occupies roughly 30% less volume once it is properly compacted.

Our stone compaction calculator applies this factor automatically, and the stone dust calculator converts your area straight into tons.

Converting Density to an Order

Suppliers price stone dust by the ton, so every project ends with the same conversion:

Running that in reverse tells you what a ton covers: one ton of stone dust is about 0.71 cubic yards, or 19.3 cubic feet, which spreads to roughly 116 sq ft at 2 inches or 58 sq ft at 4 inches before compaction.

How It Compares to Other Aggregates

Stone dust is not the heaviest aggregate by loose weight, but it has the largest gap between loose and compacted density — which is exactly why it makes such a good bedding and levelling layer, and why it is the material people most often under-order. For the difference between the terms, see stone dust vs crusher dust.

Sources

• Pavements and Pavement Design — U.S. Federal Highway Administration — federal guidance on aggregate base layers and compaction.
• National Ready Mixed Concrete Association — industry reference for aggregate unit weights and yields.