How to use the stone dust calculator
- Enter the area you will cover.
- Enter the finished depth. As a setting bed under pavers or flagstone, stone dust is usually about 1 inch. As the walking surface of a path, 2–3 inches over a compacted gravel base is common.
- Check the compaction allowance. Stone dust tightens up when tamped and wetted. The default 10% is a moderate allowance; increase it if you will compact heavily.
- Choose a bag size or bulk, and add your price.
What stone dust is good for
- Compacted paths and patios: it packs into a firm, smooth, natural-looking surface that is easy to walk and wheel on.
- Flagstone and some paver installations: it is easy to level and holds irregular stones well.
- Leveling under sheds, pools and play sets on top of a gravel base.
It is not a drainage layer. Its fine particles hold water and can stay damp, which is why many concrete paver manufacturers specify coarse concrete sand instead for the bedding layer. If you are laying manufactured pavers, read their installation guide and compare with the paver sand calculator.
The formula
Cubic feet = area × depth (in) ÷ 12 × (1 + compaction %) × (1 + waste %)
Cubic yards = cubic feet ÷ 27 · Tons = cubic feet × density ÷ 2,000
The default density is 100 lb/ft³, about 1.35 tons per cubic yard. That sits between The Engineering ToolBox values for dry sand (97 lb/ft³) and dry gravel (105 lb/ft³), which is where screenings typically fall. Damp material from an outdoor pile weighs more; the 110 lb/ft³ preset accounts for that.
Worked example
A 10 × 12 ft shed pad or patio gets a 2-inch layer of stone dust with 10% compaction and 5% waste:
- Area: 120 sq ft
- Volume: 120 × 2 ÷ 12 = 20 cu ft; × 1.10 × 1.05 = 23.1 cu ft
- Cubic yards: 0.86 yd³
- Weight: 2,310 lb = 1.16 tons
- In 50 lb bags: 47 bags
Underneath, you would normally have 4 inches of compacted base; the paver base calculator handles that layer.
Tips for working with stone dust
- Moisten and tamp. Mist the layer lightly and compact with a hand tamper or plate compactor. Dry dust will not bind.
- Build in a slight crown or slope so water runs off paths instead of softening them.
- Edge your path. Steel or stone edging keeps the edges from crumbling into beds.
- Expect some dust and tracking when dry. A top dressing of fine gravel such as pea gravel reduces it, but makes the surface looser.
- Know the color. Stone dust takes the color of the parent rock: gray for limestone or granite, reddish for some traprock and sandstone.
Frequently asked questions
How much does a yard of stone dust weigh?
Roughly 2,600 to 3,000 lb (1.3 to 1.5 tons) per cubic yard, depending on the stone and moisture. The calculator default is 2,700 lb (1.35 tons).
How much area does a ton of stone dust cover?
At 100 lb/ft³, a ton is 20 cubic feet: about 240 sq ft at 1 inch deep or 120 sq ft at 2 inches, before compaction.
How deep should stone dust be under pavers?
Usually about 1 inch as a setting bed over a compacted gravel base. Do not use it to make up for an uneven base.
Is stone dust the same as paver sand?
No. Stone dust is crushed rock fines with a wide mix of particle sizes. Paver bedding sand is a washed, coarser concrete sand that drains better.
Does stone dust harden like concrete?
It compacts very firmly but it does not chemically set. It can soften when saturated and re-firm when it dries.