Conversion factors by material
| Material | lb per yd³ | Tons per yd³ | Yd³ per ton |
|---|---|---|---|
| Crusher run / #411 | 2,900 | 1.45 | 0.69 |
| #57 crushed stonecommon | 2,700 | 1.35 | 0.74 |
| Pea gravel | 2,800 | 1.40 | 0.71 |
| River rock | 2,600 | 1.30 | 0.77 |
| Concrete sand | 2,600 | 1.30 | 0.77 |
| Mason sand | 2,500 | 1.25 | 0.80 |
| Screened topsoil | 2,200 | 1.10 | 0.91 |
| Fill dirt | 2,400 | 1.20 | 0.83 |
| Hardwood mulch | 800 | 0.40 | 2.50 |
| Asphalt (compacted) | 3,900 | 1.95 | 0.51 |
| Concrete (cured) | 4,050 | 2.03 | 0.49 |
These are loose, reasonably dry weights. Wet material can be 10–15% heavier, and if you are buying by the ton you pay for that water.
The formula, worked
Tons = cubic yards × (pounds per cubic yard ÷ 2,000). Going the other way, cubic yards = tons × 2,000 ÷ pounds per cubic yard.
Worked example: a 40 × 12 ft driveway at 4 inches of #57 stone is 5.93 cubic yards. At 2,700 lb per yard that is 5.93 × 2,700 = 16,011 lb = 8.0 tons. Add a 10% compaction allowance and you order 8.8 tons.
Reverse example: the quarry quotes you 5 tons of crusher run. That is 5 × 2,000 ÷ 2,900 = 3.45 cubic yards, which at 4 inches deep covers 279 square feet.
Why suppliers quote different units
Aggregate is almost always sold by the ton, because it is weighed over a scale and weight is what the truck is licensed for. Soil, mulch and compost are usually sold by the yard, because they are light and volume is what the customer perceives.
This means the same job can be quoted two ways, and the cheaper-looking number is often the other unit in disguise. Always convert before comparing quotes — a yard of #57 is 1.35 tons, so a "$45 per yard" quote and a "$35 per ton" quote are $45 versus $47.25 for the same material.
Moisture is the other variable and it only ever works against you. Material that has sat through rain can weigh 10–15% more per yard, so if you are buying by weight, buy on a dry day.
Frequently asked questions
How many tons is a cubic yard of gravel?
About 1.35 tons for clean crushed stone, 1.45 for crusher run with fines, and 1.30 for rounded river rock.
How many cubic yards are in a ton?
It depends on the material. Roughly 0.74 yd³ per ton for crushed stone, 0.91 for topsoil, and 2.5 for mulch.
Is there one conversion factor for cubic yards to tons?
No. Density varies from about 800 lb per yard for mulch to over 4,000 for concrete — a factor of five. Any single conversion figure is wrong for most materials.
Does wet material weigh more per cubic yard?
Yes, typically 10–15% more. If the supplier sells by weight, rain costs you money.