Formula
One page covers the stone. The dropdown is the density. #57 and river rock are the two that people search as their own calculators, so both are written out below and both are in the dropdown.
yards = (shape × depth) ÷ 27
tons = yards × (1 + waste ÷ 100) × tons per yard
#57 is clean ¾ inch crushed stone at 1.40 ton/yd³. River rock at 1–3 inches is 1.35. Flagstone at a 2 inch course is 1.45, a sandstone-class ordering weight, not a weighed pallet. General crushed stone is 1.50, and you should ask which product the yard is selling under that name. The gravel calculator uses the same #57, pea, crusher-run, and river-rock figures.
Worked examples
10 × 10 ft × 4 in of #57, no waste. 33.33 ft³ = 1.23 yd³ × 1.40 = 1.73 tons.
The same pad in river rock. The yards do not change. 1.23 × 1.35 = 1.67 tons.
A 6 × 8 ft triangle, 3 in deep. 6 ft³ = 0.22 yd³ before waste.
Reference
#57 stone
#57 is the open-graded ¾ inch stone used under slabs and in drains. This page orders it at 1.40 ton per cubic yard, 2,800 lb. A 10 × 20 ft area at 4 inches is 2.47 yards and 3.46 tons before waste. If the supplier quotes 2,700 lb or 1.35 ton, change the way you read the tons: divide by 1.40 and multiply by their number. The yards stay put.
River rock
River rock at 1–3 inches is 1.35 ton per cubic yard, 2,700 lb. It is the same calculator with a different density. A round stone does not compact the way crusher run does, so there is no compaction add-on. Coverage at 3 inches is 108 square feet per yard before waste, because 27 ÷ 0.25 = 108.
| Stone | ton/yd³ | lb/yd³ | Note |
|---|---|---|---|
| #57 stone | 1.40 | 2,800 | Clean 3/4 in crushed stone, loose ordering weight 2,800 lb/yd³. |
| River rock | 1.35 | 2,700 | 1–3 in rounds, about 2,700 lb/yd³. |
| Flagstone, 2 in thick | 1.45 | 2,900 | Sandstone-class ordering weight, about 2,900 lb/yd³. Coverage still depends on thickness and joints. |
| Crushed stone, general | 1.50 | 3,000 | About 3,000 lb/yd³. Ask the yard which product this is. |
Questions
How much does a yard of #57 weigh?
1.40 ton on this page, about 2,800 pounds, as a loose ordering figure. A dry lab weight is often closer to 1.35. The quarry ticket is the number to pay from.
How much does river rock weigh?
1–3 inch river rock is entered at 1.35 ton/yd³, about 2,700 pounds. Size and water change it. The same geometry as the gravel page, with this stone selected.
Is flagstone sold by the yard or by coverage?
This page treats a 2 inch flagstone course as 1.45 ton/yd³ so you can order a volume. Joints, thickness, and the pattern change the coverage. Ask the yard how their pallet is measured.
Sources
- #57 at 1.40 ton/yd³ and river rock at 1.35. Loose ordering figures, shared with the gravel calculator. Not a quarry specification.
- Flagstone at 1.45 ton/yd³ for a 2 inch sandstone-class course. An assumption for ordering a volume. Coverage depends on thickness and joints.