Tons come from volume times density
Work out the volume in cubic yards (feet × feet × feet, divided by 27), then multiply by density. For crushed stone that is about 1.4 tons per cubic yard. Depth in inches becomes feet by dividing by 12, so 6 inches is 0.5 ft.
Density depends on the stone
Angular crushed stone packs heavier than rounded river rock, so the ton conversion shifts with the material you order.
| Gravel type | Density (t/yd³) | Typical use |
|---|---|---|
| Crushed stone (#57) | 1.35–1.50 | Base / load-bearing layer |
| Crusher run | 1.45–1.65 | Sub-base, compacts tight |
| Pea gravel | 1.20–1.30 | Surface, decorative |
| River rock | 1.15–1.25 | Premium surface, drainage |
If you do not know the exact product, 1.4 t/yd³ is a safe default for a mixed crushed-stone driveway.
Order extra for compaction and settling
- Add 10 to 15 percent. Fresh gravel compacts by roughly that much in the first months, so the delivered tonnage should exceed the raw calculation.
- Depth matters. A driveway wants at least 4 to 6 inches; a single-layer drive really needs 8 to 12 inches to hold up under vehicles.
- Layers spread the load. A proper drive uses a coarse sub-base, a crushed-stone base and a finer surface, totaling 12 to 18 inches — calculate each layer's tonnage separately if you build it up.
Common questions
How do I convert cubic yards of gravel to tons?
Multiply cubic yards by the density in tons per cubic yard. Crushed stone runs about 1.4 tons per cubic yard, pea gravel about 1.25, river rock about 1.2. So 10 cubic yards of crushed stone is roughly 14 tons.
How many tons of gravel for a 50 by 12 foot driveway at 6 inches deep?
50 x 12 x 0.5 ft = 300 cubic feet, or 11.1 cubic yards. At 1.4 tons per cubic yard that is about 15.5 tons. Add 10 to 15 percent for compaction and you order roughly 17 to 18 tons.
Why is a cubic yard not the same as a ton?
A cubic yard measures volume and a ton measures weight. The link between them is the density of the gravel, which changes with stone type and moisture, so the same volume can weigh different amounts.
