Worked example: 4 inches deep
| Step | Math | Result |
|---|---|---|
| Area | 12 ft × 12 ft | 144 sq ft |
| Volume at 4 in | 144 × 4 ÷ 12 | 48.0 ft³ |
| Add 10% for compaction | 48.0 × 1.10 | 52.8 ft³ |
| Cubic yards | 52.8 ÷ 27 | 1.96 yd³ |
| Tons | 1.96 × 1.4 | 2.74 tons |
Gravel by depth
| Depth | Cubic feet (+10%) | Cubic yards | Tons | Bulk order (tons) | Delivered cost | 0.5 ft³ bags |
|---|---|---|---|---|---|---|
| 2 in | 24.0 | 0.98 | 1.37 | 1.5 | $168 | 53 bags / $292 |
| 3 in | 36.0 | 1.47 | 2.05 | 2.5 | $212 | 80 bags / $440 |
| 4 in | 48.0 | 1.96 | 2.74 | 3.0 | $235 | 106 bags / $583 |
| 6 in | 72.0 | 2.93 | 4.11 | 4.5 | $302 | 159 bags / $874 |
| 8 in | 96.0 | 3.91 | 5.48 | 5.5 | $348 | 212 bags / $1,166 |
At 4 inches, a bulk delivery is cheaper here ($583 in bags versus $235 delivered). Bagged gravel weighs about 5,300 lb in total for this size, so bulk is the practical way to buy for a driveway.
Prices used: bulk gravel $45 per ton plus $100 delivery (1 ton minimum); 0.5 ft³ bags $5.50. Quarry prices vary widely by stone type and region.
Patio base notes
Under pavers or flagstone, a compacted gravel base of 4 inches is typical for foot traffic, and 6 inches or more where soil is soft or frost is deep. The 1 in layer of bedding sand on top adds about 0.66 tons (sand for pavers by patio size).
For a patio finished with loose gravel instead of pavers, 2–3 inches of pea gravel over landscape fabric is enough: 1.4–2.0 tons here.
Nearby sizes
Also see 10×10 patio base , 12×16 patio base , 14×14 patio base, or the driveway and patio gravel chart. Open the gravel calculator to change the size or price.