Crushed stone calculator
A 20 × 12 ft area 4 in deep takes 2.96 cubic yards of crushed stone: about 4.00 tons spread loose, or 5.63 tons of crusher run if it is compacted as a base. Choose your stone and whether the layer will be compacted.
Which stone
Crushed stone is sold by size number. The numbers come from the AASHTO M 43 gradings that state highway departments use, and each covers a range of sizes: No. 57, for example, runs from 1 in down to stone that passes a No. 4 sieve, which has openings of about 3/16 in. Clean stone like No. 57 has no fines, so water drains through it. Crusher run (also sold as road base, dense-graded aggregate or by regional names) mixes stone with fines, so it packs hard into a firm base.
| Size | Range | Common uses |
|---|---|---|
| No. 3 | 2 to 1 in | Coarse bottom layers, drainage |
| No. 4 | 1½ to ¾ in | Coarse bottom layers, drainage |
| No. 57 | 1 in to No. 4 sieve (about 3/16 in) | Drainage, bases under slabs and pavers |
| No. 67 | ¾ in to No. 4 sieve | Drainage, paths |
| No. 8 | ⅜ in to No. 8 sieve (about 3/32 in) | Small paths, top dressing |
Local names vary, and some quarries sell their own blends of stone and dust under a number of their own. Ask your supplier what is in theirs and what it weighs per yard.
What a yard of crushed stone weighs
| Stone | Lb per cu yd | Source |
|---|---|---|
| Crushed limestone, loose | 2,550 | Caltrans |
| Crushed granite, loose | 2,600 | Caltrans |
| Crushed gravel, loose | 2,700 | Caltrans |
| Granite or limestone, loose | 2,410 to 2,590 | MoDOT |
| Trap rock, loose | 2,590 to 2,780 | MoDOT |
| Granite or limestone, compacted | 3,060 to 3,300 | MoDOT |
| Dense-graded base, compacted | 3,500 to 4,200 | WisDOT |
The calculator uses 2,700 lb (1.35 tons) per loose yard for clean crushed stone and 3,200 lb when compacted. For crusher run it uses 2,800 lb loose and 3,800 lb (1.90 tons) per compacted yard, the middle of WisDOT's 1.75 to 2.1 ton range; Caltrans plans 2.0.
Worked example
Area: 20 ft × 12 ft = 240 sq ft
240 sq ft × 4 in = 80 cu ft ÷ 27 = 2.96 cu yd
2.96 cu yd × 2,700 lb per loose cu yd ÷ 2,000 = 4.00 tons
The same area built as a compacted crusher run base 4 in thick: 2.96 cu yd × 3,800 lb per compacted cu yd ÷ 2,000 = 5.63 tons.
Area one ton covers
| Depth | Clean stone, loose (sq ft) | Crusher run, compacted (sq ft) |
|---|---|---|
| 2 in | 120 | 85 |
| 3 in | 80 | 57 |
| 4 in | 60 | 43 |
| 6 in | 40 | 28 |
Sources
- Construction and Material Specifications, Section 703: Aggregate (Table 703.01-1, sizes from AASHTO M 43), Ohio Department of Transportation, 2008 edition. Stone size numbers: No. 3 is 2 to 1 in, No. 4 is 1½ to ¾ in, No. 57 is 1 in to No. 4, No. 67 is ¾ in to No. 4, No. 8 is ⅜ in to No. 8.
- Maintenance Manual Volume 1, Appendix: Useful Information, California Department of Transportation, July 2014. Loose weights of crushed gravel, limestone, granite, screenings, sand and soil; 111 lb of asphalt mix per square yard per inch; 2.0 tons per compacted cubic yard of base.
- Highway Maintenance Tables and Conversion Factors (Engineering Policy Guide appendix), Missouri Department of Transportation, current guide. Loose and compacted weights of crushed stone, sand, asphalt and concrete in pounds per cubic foot and per cubic yard.
- Weight-Volume Relationships and Conversion Factors for Soils and Aggregates of Wisconsin (WHRP 0092-22-05), Wisconsin Highway Research Program, Michigan State University, December 2023. Measured loose and compacted weights of base aggregates, recycled asphalt and recycled concrete; tons per compacted cubic yard.
- Standard Volume-to-Weight Conversion Factors, U.S. Environmental Protection Agency, March 2016. Loose weights of gravel, rock, sand, sandy loam soil and shredded wood chips.