You measure a driveway in volume. The quarry sells it by weight. This converts between the two using the density of the material you're actually ordering, in either direction.
A driveway or a bed is a shape: length, width and depth. That gives you volume, in cubic yards. But loose aggregate is weighed on a truck scale rather than measured, so the quarry quotes tons. Neither side is being awkward — they are just measuring what is easy to measure.
The bridge between them is density, in pounds per cubic yard. Divide by 2,000 and you have tons per cubic yard. That number is the whole conversion.
| Material | lb/yd³ | Tons/yd³ | Yd³/ton |
|---|---|---|---|
| Screened topsoil | 2000 | 1.00 | 1.00 |
| Masonry sand | 2700 | 1.35 | 0.74 |
| Crushed stone | 2700 | 1.35 | 0.74 |
| River rock | 2700 | 1.35 | 0.74 |
| Pea gravel | 2800 | 1.40 | 0.71 |
These are dry-weight averages. The two things that move them are moisture and stone size — wet material can be 10 to 20 per cent heavier, and that difference is real money on a multi-ton order.
Any quarry can tell you the density of the specific product you are buying, and it will be more accurate than any table on the internet including this one. Put their number in the custom density field and the conversion uses that instead.
It matters most in the direction people forget: if you order by weight to fill a known volume and the material is heavier than you assumed, you end up short. Ordering ten tons of something you thought was 1.35 tons per yard but is actually 1.5 leaves you almost a yard down.
| Assumption | Value used |
|---|---|
| Pounds per short ton | 2000 |
| Screened topsoil density | 2000 lb/yd³ |
| Masonry sand density | 2700 lb/yd³ |
| Crushed stone density | 2700 lb/yd³ |
| River rock density | 2700 lb/yd³ |
| Pea gravel density | 2800 lb/yd³ |
Short tons, not metric tonnes. If your supplier quotes tonnes, the ticket gives that figure as well.