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Tons and cubic yards of PennDOT 2A, 2B, 1B, 3A or #4 stone, with the AASHTO equivalent and what each is for.
With these inputs:
| Result | Value |
|---|---|
| PennDOT 2A (2A modified) to order | 27.3 tons |
| Cubic yards | 18.2 yd³ |
| Truck loads | 2 × 18 tons |
| Material cost | $601 – $1,092 |
| Equivalent | — (well graded) |
| Area × depth | 720 sq ft × 6 in = 13.33 yd³ |
| Compaction (well-graded) | +30% |
| Extra | +5% |
| Weight | × 1.5 tons/yd³ |
| Typical use | Base and sub-base under asphalt, pavers and sheds; pipe bedding; compacted driveway base |
Price ranges are national bulk averages per ton before delivery. Pennsylvania quarries publish their own weights per yard — use theirs if it differs.
Pennsylvania quarries sell stone by PennDOT name: 2A is a well-graded base stone from 2 in down to fines, 2B is clean stone equal to AASHTO #57, 1B is #8, 3A is #3 and #4 is AASHTO #1 ballast. Pick the stone, enter the area and depth, and the calculator returns cubic yards, tons, truck loads and a cost range — adding the compaction allowance for 2A, which shrinks as its fines pack into the gaps.
PennDOT 2B is clean crushed stone from about 1.5 in down to 3/32 in, with almost no fines — the Pennsylvania name for AASHTO #57 stone. It drains freely, so it's used for French drains, footing drains, under slabs and as a driveway top layer.
PennDOT 2A is a well-graded stone from 2 in down to fines (up to 10% passing the #200 sieve). It was designed as a base under asphalt and compacts into a firm layer, so it's the usual base for driveways, patios, sheds and pipe bedding. "2A modified" isn't an official spec — it usually means 2A with extra fines added to bind it.
For a 60 × 12 ft driveway base 6 in deep: 13.3 yd³ in place, plus 30% because 2A compacts and 5% extra, is 18.2 yd³ — about 27.3 tons, or two tri-axle loads.
About 1.4 tons (2,800 lb) per cubic yard, the same as #57 stone. 2A is heavier per yard, about 1.5 tons, because its fines fill the gaps between the stones.
Yes. Penn State's Center for Dirt and Gravel Road Studies lists PennDOT 2B as AASHTO #57, 1B as #8, 3A as #3 and #4 as AASHTO #1. Outside Pennsylvania, ask for the AASHTO number.
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