Worked example: 4 inches deep
| Step | Math | Result |
|---|---|---|
| Area | 12 ft × 16 ft | 192 sq ft |
| Volume at 4 in | 192 × 4 ÷ 12 | 64.0 ft³ |
| Add 10% for compaction | 64.0 × 1.10 | 70.4 ft³ |
| Cubic yards | 70.4 ÷ 27 | 2.61 yd³ |
| Tons | 2.61 × 1.4 | 3.65 tons |
Gravel by depth
| Depth | Cubic feet (+10%) | Cubic yards | Tons | Bulk order (tons) | Delivered cost | 0.5 ft³ bags |
|---|---|---|---|---|---|---|
| 2 in | 32.0 | 1.30 | 1.83 | 2.0 | $190 | 71 bags / $390 |
| 3 in | 48.0 | 1.96 | 2.74 | 3.0 | $235 | 106 bags / $583 |
| 4 in | 64.0 | 2.61 | 3.65 | 4.0 | $280 | 141 bags / $776 |
| 6 in | 96.0 | 3.91 | 5.48 | 5.5 | $348 | 212 bags / $1,166 |
| 8 in | 128.0 | 5.21 | 7.30 | 7.5 | $438 | 282 bags / $1,551 |
At 4 inches, a bulk delivery is cheaper here ($776 in bags versus $280 delivered). Bagged gravel weighs about 7,050 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 0.88 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: 1.8–2.7 tons here.
Nearby sizes
Also see 12×12 patio base , 14×14 patio base , 10×10 patio base, or the driveway and patio gravel chart. Open the gravel calculator to change the size or price.