Crusher run is crushed stone that has not been washed — the quarry runs rock through the crusher and sells the output as-is, fines and all, instead of screening the dust out. Those fines are not a flaw; they are the entire point. Mixed with the larger stone chips, they fill every gap during compaction and lock the material into a dense, nearly solid layer, which is why crusher run is the default base under driveways, patios, sheds, and roads almost everywhere in the country.
The confusing part is the name. Ask for “crusher run” in one region and get a blank look, because the same product is sold under a different name a few states over — and sometimes as an entirely separate spec with its own gradation table.
Regional Names for the Same Basic Product
Every one of these is a dense-graded stone-and-fines blend built to compact hard, though exact gradation specs can vary slightly by quarry and by state DOT standard.
| Name | Common Region | Notes |
|---|---|---|
| Crusher run / crush and run | Southeast, general use nationwide | The generic, most widely recognized name |
| #411 | Southeast (esp. Tennessee, Carolinas) | Blend of #57 stone with stone dust added |
| 2A modified | Mid-Atlantic, Pennsylvania | PennDOT spec, up to 2-inch top size with fines |
| DGA (Dense Grade Aggregate) | Northeast, New York/New Jersey | Same dense-graded concept, DOT-specified gradation |
| Road base / base course | West, generic nationwide | Functional name describing the use, not a fixed spec |
None of these are guaranteed to be identical stone-for-stone — a DOT-spec 2A modified has tighter gradation tolerances than a quarry’s generic “crusher run” pile — but functionally, all of them are the same idea: crushed stone left dirty on purpose so it compacts into a structural layer. If a project spec calls out a specific one of these by name, ask the quarry to match that spec rather than assuming any dense-graded product will do.
Why the Fines Matter So Much
Washed, open-graded stone like #57 holds 36–42% void space between the stones — gaps that let water pass through freely but that also mean the material can never compact into anything solid; the stones just rearrange under a plate compactor. Crusher run’s fines fill those exact gaps. Under compaction, dust and small chips pack in around the larger stones, closing off the voids and creating a layer that spreads load and resists rutting almost like a weak pavement.
That same trait is a liability anywhere drainage is the goal. Compacted crusher run sheds water off the surface rather than letting it through, which is exactly wrong for a French drain or the backfill behind a retaining wall — put dense-graded material there and you have built a dam instead of a drain. Full comparison of the two use cases in #57 Stone vs Crusher Run.
Buying tip: When calling a quarry, describe the use (“driveway base,” “under a shed pad”) rather than just asking for “crusher run” by name — dispatchers in your region may know the product by #411, 2A, DGA, or another local term entirely, and describing the job avoids a mismatched order.
Typical Gradation
Most crusher run blends top out around 3/4 inch to 1 inch stone, grading continuously down through smaller chips to dust, with roughly 10–15% of the mix passing the finest screens as true fines. That continuous gradation — big stone, medium stone, small stone, dust, all in one pile — is what a washed single-size product like #57 or #67 never has, and it is the reason crusher run compacts while clean stone never does.
Installing and Compaction
Crusher run compacts best in lifts no deeper than about 4 inches, each one run over with a plate compactor before the next lift goes down — trying to compact a full 6–8 inches in one pass leaves the bottom loose no matter how long you run the plate over the top. Expect the loose material to lose roughly 10–15% of its depth once compacted, so order and spread accordingly; a driveway spec’d for 4 inches compacted needs closer to 4.5–4.75 inches loose before you start.
Cost and Ordering
Crusher run runs about 1.5 tons per cubic yard, the same as most crushed stone, and typically prices at $25–$45 per ton — often toward the lower end of that range since it skips the washing step that clean stone requires. A 12×50-foot driveway base at 4 inches compacted depth needs roughly 7.5 cubic yards, or about 11 tons loose once you account for compaction loss. Size your own project with the crusher run calculator, and if you are deciding between a full crusher run base or a layered build with a clean-stone drainage course underneath, the gravel driveway calculator handles the combined layers.
Is It Really Crusher Run? How to Check a Delivery
Mislabeling happens — a driver grabs from the wrong stockpile, or a supplier’s “crusher run” is really just screened #57 with a little dust added rather than a true dense-graded blend. A few checks on the pile before you spread it will catch a mismatch:
- Look for dust and fines. Grab a handful from the middle of the pile. True crusher run leaves a visible film of fine dust on your palm and has a continuous range of particle sizes from dust up to about 3/4–1 inch. If the handful is all clean, uniform stone with no dust and no fines, it’s washed #57 or #67, not crusher run.
- Check the color consistency. Genuine crusher run has a fairly uniform gray-tan color throughout, since it’s all crushed from the same parent rock at one quarry. A pile with an odd mix of colors or occasional flecks of asphalt or brick can indicate recycled material sold under the crusher run name — not necessarily bad, but you should know what you’re getting and price it accordingly.
- Squeeze-and-drop test. Grab a damp handful and squeeze it into a loose ball, then drop it from waist height onto a hard surface. Real crusher run with adequate fines will hold together briefly before breaking apart. A handful that never binds at all, crumbling to individual stones the instant you release your grip, is lower on fines than a proper dense-graded product should be.
- Ask for the delivery ticket’s material code. Most quarries print a product code or spec name on the ticket. If it says “#57” or “washed stone” but you ordered crusher run, that’s a paperwork mismatch worth a phone call before you spread a wrong load across a driveway base.
Testing Compaction at Home
Professional compaction testing uses a nuclear density gauge or a Proctor test in a lab, neither of which a homeowner has access to. A few low-tech checks get you most of the way to knowing whether a lift is compacted enough to build on:
- The heel-drop test. Stand on the compacted surface and drop your full weight onto one heel. Properly compacted crusher run barely deflects — you’ll feel almost no give. If your heel visibly sinks or leaves a dent, that lift needs more passes with the plate compactor before the next layer goes down.
- The screwdriver test. Push a long flathead screwdriver into the compacted surface by hand. It should be difficult to push in more than an inch or two without real effort. Sliding in easily to several inches means the material underneath is still loose.
- The wheelbarrow test. Roll a loaded wheelbarrow across the compacted lift. Properly compacted crusher run leaves at most a faint tire track with no rutting. Visible ruts or a wheelbarrow that feels like it’s pushing through loose material means more compaction passes are needed.
- Visual settling check. After compaction, the loose material should visibly shrink by roughly 10–15% in depth — that’s the fines and chips locking together and closing the voids. If a freshly compacted lift looks the same height as before you ran the plate over it, the compactor likely isn’t achieving real density, whether from too few passes, a lift that was too deep, or material that’s too dry (dry crusher run compacts poorly; a light misting before compacting helps the fines bind).
None of these replace an engineer’s compaction test on a job that requires one, but for a residential driveway, patio base, or shed pad, passing all four checks is a reliable sign the base will hold up under real-world loads.
Bottom Line
Crusher run, crush and run, #411, 2A modified, and DGA are regional names for the same core idea: crushed stone sold with its fines left in so it compacts into a structural base. Order it by describing the job to your supplier, plan for 10–15% compaction loss, and reach for washed #57 or #67 instead any time the goal is drainage rather than a hard surface.