Crushed stone calculator: which stone?
Pick clean, open-graded stone such as #57 for drainage and loose cover, and dense-graded stone such as crusher run for a base that locks together. US aggregate sizes run from #1 (largest) to #10 (screenings), and two-digit sizes are blends of two sizes.[1]
| Grade | Size range | Source |
|---|---|---|
| #1 | 4 in to ¾ in | [1] |
| #3 | 2½ in to ½ in | [1] |
| #57 | about 1 in down to 3/16 in, little or no fines | [1] |
| #8 | about 3/8 in down to the No. 8 sieve | [1] |
| #10 (screenings, stone dust) | under 3/8 in | [1] |
| PennDOT 2A (dense-graded) | 2 in down to fine, 0–10% fines | [1] |
| Dense-graded base | 1½ or ¾ in down to fines | [5] |
57 stone calculator: weight and coverage
A cubic yard of loose clean crushed stone weighs about 2,700–3,100 lb (1.35–1.55 US tons).[2] We found no primary source with a separate figure for #57, so this site uses the general gravel range for it.
| Depth | Cubic yards | US tons | Sq ft per ton |
|---|---|---|---|
| 2 in | 0.62 | 0.83–0.96 | 104–120 |
| 3 in | 0.93 | 1.25–1.44 | 70–80 |
| 4 in | 1.23 | 1.66–1.91 | 52–60 |
| 6 in | 1.85 | 2.5–2.87 | 35–40 |
Crusher run calculator: base and compaction
Crusher run is dense-graded stone that is spread loose and then compacted, so order about 17% more than the finished volume: loose sand or gravel compacts to about 0.86 of its volume.[2] Set the compaction field in the calculator for base work.
Published weights for dense-graded base vary: a New Mexico state conversion table gives base course as 1.25 tons per cubic yard,[3] and Penn State's ordering figure for its dense-graded road aggregate works out to about 1.62 tons per loose yard.[4] The calculator uses that span for crusher run, so ask your supplier for their figure if you order by the ton.
Driveways and patiosFor layered builds, use the driveway gravel calculator or the paver base calculator, which size each layer separately.
How deep should crushed stone be?
Two inches is a practical minimum for a stone path, and 4 inches if thick stones or pavers are set into it; angular stone packs into a nearly solid surface, while rounded river-run gravel never packs down completely.[6] Decomposed granite ground covers use 1–2 inches.[7] Under paving, bases are measured compacted; see the gravel depth table.
Common stone ordering mistakes
The most common mistake is ordering clean stone where a compacted base is needed: #57 has little fine material to lock it together, while dense-graded stone does.[1]
- No compaction allowance for crusher run: add about 17%.[2]
- Mixing tons and yards without the weight: clean stone is about 1.35–1.55 tons per yard.
- Too thin a path: under 2 inches the ground shows through.[6]
Frequently asked questions
How much crushed stone do I need?
Square feet × depth in inches ÷ 324 = cubic yards. A 10 × 12 ft area 4 inches deep is 1.48 yd³.
How much does a yard of 57 stone weigh?
About 2,700–3,100 lb loose, using the general crushed stone range.[2]
What is crusher run?
Dense-graded crushed stone that runs from the top size down to fine dust, so it compacts into a firm base. PennDOT 2A, for example, is 2 inches down to fine with 0–10% fines.[1]
How many tons of crushed stone do I need for a driveway?
For 12 × 50 ft at 6 inches: 11.1 cubic yards, about 15–17 tons of clean stone before compaction.
Sources
- Aggregate 101 (DSA Handbook Appendix F)
- FM 5-434 Earthmoving Operations, Tables 1-1 and 1-2 (material weights, swell and conversion factors)
- Conversion Factors for Construction Materials and Common Minerals (from BLM Handbook H-3890-1)
- Driving Surface Aggregate (DSA) Handbook
- Glossary of Terms for Segmental Concrete Pavement (PAV-TEC-001-23)
- Gravel Pathways in the Garden
- Ground Covers for Arizona Landscapes (AZ1110)