How this crushed concrete calculator works
Recycled concrete estimates exactly like virgin stone — volume times density — just a touch lighter, because the old mortar clinging to the aggregate is porous:
tons = yd³ × 1.35 (21AA) × (1 + waste%) → rounded up to ¼ ton
At the defaults — a 40 × 10 ft drive, 4 in, 10% allowance — the scale order is 7.5 tons, about $225; the full chain is in the load math section below.
What is crushed concrete?
Crushed concrete is demolition concrete — old slabs, foundations, pavement — run back through a crusher and screened to size. Diverted from the landfill, it’s the greenest and cheapest base a yard sells, and it does one thing virgin stone can’t:
It re-cements
The residual portland cement in the fines reactivates when the material is compacted damp, so a crushed-concrete base tightens into a near-solid, almost-paved mat over its first season. That self-binding is why it resists rutting better than loose gravel.
21AA graded base
The dense-graded product — fines up to about 1 in — that compacts tight, the recycled twin of 21AA limestone. This is the base grade, the calculator’s default at 1.35 t/yd³.
#57 clean recycled
Fines-free recycled stone for drainage and fill, a little lighter at 1.3 t/yd³ — the recycled answer where you’d otherwise use clean #57.
Against virgin stone
As a compacted structural base it performs like dense-grade limestone at 30–50% less; the road base calculator prices the virgin version, and the difference is mostly the landfill you avoided.
How deep should crushed concrete be?
Crushed concrete is a base, so its depth follows base duty — and the one thing it asks that virgin stone doesn’t is to be compacted damp, so the cement fines wake up and re-bind. What each job wants:
- Gravel driveway base: 4–6 in compacted on firm ground, 6–8 over soft, in lifts.
- Under a concrete slab or pavers: 4 in of compacted 21AA.
- Under asphalt: 6–8 in — the same duty as virgin base.
- Fill and grading: the cheap way to build up grade under future hardscape.
- Compact it damp so the fines re-cement; dry-placed material never sets the same way.
How much does a ton of crushed concrete cover?
Table 1 is coverage per ton of 21AA by depth; Table 2 is the price advantage against virgin stone.
| Depth | 1 ton covers |
|---|---|
| 3″ | 80 ft² |
| 4″ | 60 ft² |
| 6″ | 40 ft² |
| Material | Per ton |
|---|---|
| Crushed concrete | $15–35 |
| Crushed limestone | $30–55 |
| Virgin crushed stone | $35–60 |
How to measure for crushed concrete
- Measure the area — driveway length × width, or the slab/paver footprint; total odd shapes first.
- Set the compacted depth from the depth guide — 4 in under pavers, 4–6 in a driveway base.
- Pick 21AA graded for a compacting base, or #57 recycled for drainage — the density differs.
- Leave the allowance at 10% for compaction and spillage.
- Enter the per-ton price — call the nearest crushing yard, since supply and price are both local.
Worked example: crushed concrete for a 40 × 10 drive
The default, worked line by line — 40 × 10 ft, 4 in of 21AA at 1.35 t/yd³, 10% allowance, $30 a ton:
volume = 400 × (4 ÷ 12) = 133 ft³ = 4.94 yd³
weight = 4.94 × 1.35 = 6.7 tons exact
allowance = 6.7 × 1.10 = 7.33 → order 7.5 tons
cost = 7.5 × $30 = $225 · 1 ton covers 60 ft² at 4″
The same 7.5-ton lift in virgin limestone or crushed stone would run half again more — $340–450 against $225. Over a whole driveway, the recycled choice is the difference between one weekend’s material budget and two, for a base that performs the same once it’s compacted and re-cemented.
The catch is supply, not performance: crushed concrete is only cheap near a crushing yard, because it doesn’t travel far before the haul erases the savings. Call the nearest C&D recycler for a delivered per-ton number before you count on the discount — where it’s local, it’s the obvious base; where it isn’t, virgin dense-grade may win once trucking is in.
What this crushed concrete estimate doesn’t include
The calculator prices the recycled base on the scale itself. As with any base course, the surface above it and the site work below it are separate lines — list them all before the total is a real budget:
- A decorative top course. Crushed concrete is a base, not a finish — cap it with #57 or pavers for looks.
- Delivery. A per-load haul fee, often the bigger share of a cheap material.
- Geotextile fabric. Under the base on soft or clay ground.
- Compaction equipment. A plate compactor, run damp so the fines re-cement.
- Excavation. Cutting the lane and hauling off spoil.
- Grading. Shaping the crown and raking flat.
Crushed concrete FAQ
How much crushed concrete do I need?
Volume × 1.35 tons per cubic yard: the default 40 × 10 ft driveway lift at 4 in is 4.94 yd³ — 6.7 tons, ordered as 7.5 with 10% compaction allowance, about $225 at $30 a ton.
Is crushed concrete good for driveways?
Yes — it is one of the best budget driveway materials. The residual cement fines re-bind as the material weathers, so a compacted crushed-concrete drive tightens into an almost paved surface that sheds rutting better than loose gravel.
How many tons of crushed concrete are in a cubic yard?
About 1.35 tons for graded 21AA with fines, a touch less for clean #57 recycled at 1.3 — recycled concrete runs slightly lighter than virgin limestone because the old mortar is porous.
What is 21AA crushed concrete?
A dense-graded recycled base: crushed concrete screened from fines up to about 1 in, the recycled twin of 21AA limestone base. The full gradation is what lets it compact tight and re-cement. "21AA" is a Michigan DOT designation that has become a common name for the graded recycled base nationwide.
How much cheaper is crushed concrete than gravel?
Commonly 30–50% less: $15–35 per ton in 2026 against $35–60 for virgin crushed stone, because the feedstock is demolition waste diverted from landfill. Supply is local — near a crushing yard it is the obvious base choice.
Where should you not use crushed concrete?
Skip it as a decorative surface — the color is grey-to-mixed and rebar flecks can surface — and as clean drainage stone, since the fines hold water where a French drain wants none. It also runs alkaline, which some plantings dislike. As a compacted structural base under drives, slabs and pavers, though, it is excellent.
How much does a ton of crushed concrete cover?
60 ft² at 4 in deep — 80 ft² at 3 in, 40 at 6 in. The live coverage figure under the drawing tracks whatever depth you set.
Sources and standards
- ASTM D2940 / recycled-aggregate provisions: graded base requirements that recycled concrete is screened to meet.
- State DOT recycled-base specs (e.g. 21AA): the graded-recycled designations quarries sell under.
- EPA C&D recycling guidance: the demolition-diversion practice that makes crushed concrete the green base.
- The scale ticket: recycled runs a touch lighter and moisture moves it — the weighed load governs.
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