Crushed stone is sold by number, and the numbering runs backwards from what most people expect: the bigger the number, the smaller the stone. #1 stone is fist-sized rock at 2–4 inches. #10 is essentially dust. Order the wrong number and you get boulders where you needed screenings — an expensive mistake to shovel back onto a truck.
Crushed stone itself is quarried rock — usually limestone, granite, or trap rock — that has been blasted, mechanically crushed, and sorted through screens into consistent size ranges called gradations. The angular, fractured faces are the whole point: unlike rounded gravel, crushed stone locks together under load. Here is the complete chart, followed by what each size actually does.
| Stone Number | Size Range | Best For |
|---|---|---|
| #1 | 2–4 inches | Culvert protection, construction entrances, stabilizing deep mud |
| #2 | 1.5–2.5 inches | Railroad ballast, heavy-equipment pads, driveway sub-base |
| #3 | 1–2 inches | Drainage beds, dry wells, first lift of a new driveway |
| #57 | 1/2–1 inch | The all-purpose size: concrete aggregate, French drains, driveways |
| #67 | Up to 3/4 inch | Concrete mixes, pipe bedding, tighter finish layers |
| #8 | 3/8 inch | Asphalt mixes, paver bedding, walkway topping |
| #10 | Screenings / dust | Paver leveling beds, horse arenas, walkway fines |
How the Numbering System Works
The numbers come from the screens quarries use to sort crushed rock. A single-digit grade like #3 means the stone passed one screen and was caught by the next, so nearly every piece falls inside a tight size band. Two-digit designations are blends: #57 stone spans the range from size #5 down to size #7, which is why it runs from roughly half an inch up to a full inch. Blends pack better than single sizes because the smaller pieces nest between the larger ones.
One more distinction matters before you order. “Gravel” in the strict sense is naturally rounded river-worn stone; crushed stone is angular. Suppliers use the words loosely, but the performance difference is real — angular stone interlocks and stays put, rounded stone rolls and migrates.
The Big Sizes: #1, #2, and #3
#1 stone (2–4 inches) is the largest standard gradation — individual rocks the size of a softball. It is too large to walk on comfortably and too large to shovel. Use it where bulk and mass matter: lining culvert inlets, building construction entrances that scrape mud off truck tires, or choking a soft, boggy spot that swallows smaller stone.
#2 stone (1.5–2.5 inches) is the classic railroad ballast size. On residential jobs it shows up as the sub-base under driveways that carry heavy trucks, and as a stable working pad for equipment on wet sites.
#3 stone (1–2 inches) is the most useful of the large grades. It is the standard first lift for a new gravel driveway over raw soil, the fill for dry wells, and a common drainage bed stone. Big enough to bridge soft ground, small enough that a loader spreads it cleanly.
The Workhorse Blends: #57 and #67
#57 stone (1/2–1 inch) is the most commonly ordered crushed stone in America, full stop. It is the default aggregate in ready-mix concrete, the standard fill for French drains and foundation perimeter drains, the go-to bedding under slabs, and a popular driveway topping. If a supplier says “clean stone” with no other detail, they usually mean #57. Estimate your tonnage with the #57 stone calculator before you call the quarry.
#67 stone (up to 3/4 inch) is #57’s slightly smaller sibling. It behaves almost identically but tucks into tighter spaces: pipe bedding, thinner concrete pours, and finish layers where a full 1-inch top size looks coarse. Many DOT specs call for #67 specifically. Size an order with the #67 stone calculator.
The Fine Grades: #8 and #10
#8 stone (3/8 inch) is pea-sized angular chip. It dominates asphalt mixes and is the modern spec for permeable paver bedding, where its angularity keeps pavers from shifting the way rounded pea gravel allows.
#10 stone — better known as screenings, stone dust, or fines — is everything that falls through the smallest screen. It compacts into a hard, smooth surface, which makes it the traditional leveling bed under pavers, the footing in horse arenas, and the finish layer on fine gravel paths.
Open-Graded vs Dense-Graded: The Distinction That Matters Most
Every product above is open-graded: washed, single-size-band stone with no fines. Open-graded stone holds 36–42% empty void space, which is why it drains brilliantly — and why it never compacts into a truly solid mass. The stones just rearrange.
Dense-graded products — crusher run, #411, 2A modified — take the opposite approach: they deliberately mix stone with fines all the way down to dust, so the blend compacts into a near-solid layer. Dense-graded is what you want for a structural base; open-graded is what you want for drainage. Read the full breakdown in What Is Crusher Run?, and size a dense-graded base with the crusher run calculator.
Buying Advice
Crushed stone weighs about 1.5 tons per cubic yard, and most quarries sell by the ton at roughly $25–$45 depending on region and size. To convert a project into tons: length × width × depth (in feet) ÷ 27 gives cubic yards; multiply by 1.5 for tons. Or skip the math and use the crushed stone calculator.
- Order 5–10% extra — settling and spillage always eat some.
- Ask for “washed” stone if you need drainage; dusty stone clogs fabric and pipe.
- Delivery is usually cheaper per ton the more you order; a full triaxle load (20+ tons) often costs little more to deliver than 5 tons.
- Confirm the local name. The same stone may be “#57,” “3/4 clean,” or “57s” depending on the quarry.
How to Identify Stone Size Without a Gauge
A delivery shows up and you want to confirm you got what you ordered before the truck leaves, but nobody carries a sieve stack around. The fastest check is comparing a handful of stone against everyday objects you already know the size of. Grab a piece from the middle of the pile, not the dusty edge, and hold it next to one of these:
- #10 (screenings): feels like coarse sand or sugar between your fingers — no individual “stones” to speak of.
- #8: about the size of a pencil eraser or a small pea, roughly 3/8 inch.
- #67: a bit larger than a chickpea, up to about 3/4 inch — close to the diameter of a US quarter (0.96 in).
- #57: ranges from quarter-sized up to roughly a golf ball’s diameter (1.68 in) at the top end.
- #3: tennis-ball to lemon sized, 1–2 inches.
- #2: baseball to orange sized, 1.5–2.5 inches.
- #1: softball to grapefruit sized, 2–4 inches — the largest piece you’d still call “stone” rather than “rock.”
For a more precise check, lay a tape measure flat on the tailgate and drop a dozen random pieces on it — if most cluster within the stated range, the load matches the ticket. A load with a wide scatter of sizes, or a noticeable amount of dust and fines mixed into what should be washed #57, is worth a call back to the quarry before you spread it.
Regional Naming Variance: Why “#57” Isn’t Always #57
The number system above is the ASTM C33 standard, and most quarries build their gradations around it — but “most” is not “all.” Individual state DOT specifications adjust the sieve tolerances slightly, and some states use their own numbering on top of it. What ships as “#57” in Georgia and what ships as “#57” in Ohio will both fall roughly in the 1/2–1 inch range, but the exact sieve-passing percentages at each screen size can differ enough to matter on a spec’d job.
- Pennsylvania: PennDOT uses its own 2A, 2B, and 2RC designations alongside the standard numbers — 2B is roughly equivalent to a clean #57/#67 blend, but is not interchangeable on a spec’d project without an engineer’s sign-off.
- New York: NYSDOT sizes stone by its own “Size 1” through “Size 4” system rather than the national #1–#10 chart, which trips up out-of-state buyers constantly.
- Texas: TxDOT grade numbers (Grade 1 through Grade 8) run on a completely separate scale from the ASTM chart above — a Texas “Grade 4” is not the same as a national “#4.”
- Generic supplier terms: “3/4 clean,” “1-inch clean,” and “57s” are all informal names quarries use for stone that is approximately #57 or #67 — close enough for a residential driveway, not close enough for a stamped engineering spec.
For residential work — driveways, drains, landscaping — the informal regional name is almost always fine as long as you describe the use to the counter person. For anything with an engineer’s spec sheet attached (retaining wall drainage, a municipal permit, a commercial pad), ask the quarry for their actual gradation sieve analysis and match it to the spec by percentage passing, not by the number alone.
Bottom Line
Remember three things and you can order confidently: bigger number means smaller stone, #57 is the safe all-purpose answer, and clean stone drains while stone-plus-fines compacts. When the choice comes down to the two most common products, our comparison of #57 stone vs crusher run settles it in five minutes.
