Gravel Calculator
Tons and cubic yards of gravel, crushed stone or road base for driveways, paths, drainage and paver bases.
Gravel formula
tons = area × depth (in) ÷ 12 ÷ 27 × (1 + extra) × t/yd³
The weight per yard is what trips people up: a yard of pea gravel and a yard of river rock take the same space but not the same weight, and a yard of dry decomposed granite weighs less than a yard of wet crushed base. The figures above are typical loose weights published by quarries; your supplier’s scale ticket is the final word.
Which stone for which job
| Material | Best for | t/yd³ | Sq ft/ton at 3″ |
|---|---|---|---|
| Crushed base / road base (ABC, ¾″ minus) | Paver & driveway base, compacts hard | 1.4 | 77 |
| Clean crushed stone #57 (¾″) | Drainage, driveway top, wall backfill | 1.35 | 80 |
| Pea gravel | Paths, play areas, patios | 1.4 | 77 |
| River rock (1–3″) | Dry creek beds, borders | 1.35 | 80 |
| Decomposed granite | Rustic paths and patios | 1.3 | 83 |
| Stone dust / screenings | Flagstone bedding, fill between stones | 1.35 | 80 |
| Concrete sand (bedding) | Paver bedding course | 1.35 | 80 |
| Topsoil / fill dirt | Grading and lawn prep | 1.1 | 98 |
Questions people ask
How do I calculate how much gravel I need?
Area in square feet × depth in inches ÷ 12 gives cubic feet; divide by 27 for cubic yards; multiply by the material’s weight (about 1.4 tons per yard for most gravel) for tons. A 10×20 area at 3 inches deep is 50 cu ft = 1.85 yd³ ≈ 2.6 tons.
How much does a ton of gravel cover?
At 2 inches deep, one ton of typical gravel (1.4 t/yd³) covers about 115 sq ft; at 3 inches, about 77 sq ft; at 4 inches, about 58 sq ft.
How deep should gravel be for a driveway?
A gravel driveway is usually built in layers totalling 8–12 inches: a coarse sub-base (e.g. #3 stone), then 4 inches of crushed base with fines, topped with 2–3 inches of a surface stone like #57 or crusher run.
How much gravel for a path or patio?
Decorative paths and pea-gravel patios need 2–3 inches of top stone over a compacted crushed base of 3–4 inches. Use steel or paver edging so it stays put.
What is crushed stone vs. gravel?
Crushed stone is quarried rock broken by machines, with sharp angular faces that lock together — good for bases and driveways. Gravel in the strict sense is naturally rounded stone (pea gravel, river rock) that rolls underfoot and doesn’t compact.