Pavers plus this gravel as the base, in one project view.
Gravel Calculator
Bases & masonryQuick answer: gravel is bought by the ton or the yard, and the bridge between them is density. This calculator gives both, by stone type. A 20×10 ft driveway topped 4 inches deep needs 2.47 cubic yards — about 3.46 tons of standard crushed gravel.
Tons use the standard estimating density for the stone type you pick. Loose gravel compacts about 20-25% under a roller or plate compactor — depths here are finished depths, so for a base layer that will be compacted, add the extra allowance.
How it works — the formula
Volume (ft³) = Length (ft) × Width (ft) × Depth (in) ÷ 12 · Cubic yards = ft³ ÷ 27 Tons = Cubic yards × Density (t/yd³)| Stone type | Estimating density | Typical use |
|---|---|---|
| Crushed stone / standard gravel | 1.40 t/yd³ | Driveways, slab bases, drainage |
| Pea gravel | 1.30 t/yd³ | Paths, play areas, landscaping |
| River rock | 1.35 t/yd³ | Decorative beds, drainage |
| Decomposed granite | 1.45 t/yd³ | Paths and patios in dry climates |
Densities are estimating averages used across the stone trade; moisture and exact gradation move a real load by about ±10%. That is exactly why yards sell by the ton at the scale house — your invoice weight is the truth, this page is the plan.
Worked examples
| Project | Cubic yards | Tons | Est. cost at $55/t |
|---|---|---|---|
| Driveway 20 × 10 ft, 4 in deep, crushed stone | 2.47 yd³ | 3.46 t | $190 |
| Path 10 × 10 ft, 2 in deep, pea gravel, 10% extra | 0.68 yd³ | 0.88 t | $49 |
| Parking pad 30 × 12 ft, 3 in deep, river rock | 3.33 yd³ | 4.50 t | $248 |
Check the first row: 20 × 10 × (4 ÷ 12) = 66.7 ft³ = 2.47 yd³. Times 1.40 t/yd³ for crushed stone = 3.46 tons.
Frequently asked questions
How many tons of gravel do I need for a driveway?
20×10 ft at 4 in deep: 2.47 yd³ ≈ 3.46 tons of crushed stone. A 12×40 ft driveway at the same depth: ≈8.3 tons.
How many cubic yards are in a ton of gravel?
≈0.71 yd³ per ton for crushed stone (1 ÷ 1.40); ≈0.77 for pea gravel; ≈0.69 for decomposed granite.
How deep should driveway gravel be?
4 in compacted minimum for cars; 6 in in two layers lasts longer, especially on clay.
Bags or bulk — which is cheaper?
Bulk by far: ≈$40–$70/ton bulk vs the equivalent of $150+/ton bagged. Bags only win under about half a ton.
How much area does one ton cover?
Crushed stone: ≈230 ft² at 1 in, ≈115 ft² at 2 in, ≈58 ft² at 4 in deep.
Related tools
Yards for a poured driveway instead of gravel.
Bags and yards for the beds along the driveway.
The bedding layer that goes over a gravel base.
See the full list on the Home & DIY Calculators page.
Estimates only. Stone density varies with gradation and moisture; your supplier's scale weight governs the invoice. Depths are finished depths — allow extra for compaction on base layers.