Gravel driveway calculator
A driveway 100 ft long and 12 ft wide, with 4 in of compacted crushed stone under 2 in of compacted crusher run, takes about 37.78 tons of stone: 23.70 tons for the bottom layer and 14.07 for the top.
Why driveway stone is counted compacted
A driveway is rolled or plate-compacted, and compaction squeezes the air out of the stone. A yard of stone measured in place on a finished driveway weighs much more than a yard in the truck. Research for the Wisconsin Department of Transportation measured base aggregates swelling by 27 to 60 percent between their compacted and loose states, and WisDOT converts compacted base at 1.75 to 2.1 tons per cubic yard. Caltrans plans 2.0 tons per compacted yard.
So enter the finished, compacted thickness of each layer. The calculator multiplies the compacted volume by a compacted weight to get the tons to order, and also shows roughly how many loose yards that is on the truck.
Area: 100 ft × 12 ft = 1,200 sq ft
Bottom: 1,200 sq ft × 4 in ÷ 27 = 14.81 cu yd × 3,200 lb ÷ 2,000 = 23.70 tons
Top: 1,200 sq ft × 2 in ÷ 27 = 7.41 cu yd × 3,800 lb ÷ 2,000 = 14.07 tons
Tons per 100 ft of a 12 ft driveway
| Material | Tons per compacted cu yd | 2 in | 4 in | 6 in | 8 in |
|---|---|---|---|---|---|
| Crusher run (road base with fines) | 1.90 | 14.07 | 28.15 | 42.22 | 56.30 |
| Crushed stone (#57 and other clean stone) | 1.60 | 11.85 | 23.70 | 35.56 | 47.41 |
| Asphalt millings (recycled asphalt) | 1.70 | 12.59 | 25.19 | 37.78 | 50.37 |
| Crushed concrete (recycled) | 1.70 | 12.59 | 25.19 | 37.78 | 50.37 |
Loose and compacted weights
| Material | Lb per loose cu yd | Tons loose | Lb per compacted cu yd | Tons compacted |
|---|---|---|---|---|
| Crusher run (road base with fines) | 2,800 | 1.40 | 3,800 | 1.90 |
| Crushed stone (#57 and other clean stone) | 2,700 | 1.35 | 3,200 | 1.60 |
| Asphalt millings (recycled asphalt) | 2,400 | 1.20 | 3,400 | 1.70 |
| Crushed concrete (recycled) | 2,300 | 1.15 | 3,400 | 1.70 |
The crushed stone figure is MoDOT's compacted weight for granite or limestone. Asphalt millings and crushed concrete come from the Wisconsin measurements of recycled asphalt and recycled concrete base, which compacted to 1.64 to 1.71 and 1.65 to 1.75 tons per cubic yard.
Layers
A common build is a coarse stone base topped with a finer stone that has fines in it, so the surface packs hard and sheds water. The calculator takes up to two layers; set the top layer's depth to 0 for a single layer. Thick layers compact more evenly when spread and compacted a few inches at a time, so a deep base is usually built in lifts.
Sources
- 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.
- 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.