Gravel for 12 × 20 ft by depth
| Depth | Cu ft | Cu yd | Tons, gravel | Tons, crushed stone | 0.5 cu ft bags |
|---|---|---|---|---|---|
| 2 in | 40 | 1.48 | 2.10 | 2.22 | 80 |
| 3 in | 60 | 2.22 | 3.15 | 3.33 | 120 |
| 4 in | 80 | 2.96 | 4.20 | 4.44 | 160 |
| 6 in | 120 | 4.44 | 6.30 | 6.67 | 240 |
| 8 in | 160 | 5.93 | 8.40 | 8.89 | 320 |
| 12 in | 240 | 8.89 | 12.6 | 13.3 | 480 |
Gravel at 1.42 t/yd³ (Engineering ToolBox); crushed stone at 1.50 t/yd³ (Hello Gravel). No extra added.
Rochester Concrete Products' install guide adds 10% for compaction and uneven ground. A 12x20 pad is a common size for a shed, hot tub or patio; see the project calculators for the depth each one calls for.
Working it out
240 sq ft × depth (in) ÷ 12 ÷ 27 = cubic yards
At 4 inches: 240 × 4 ÷ 12 = 80.0 cubic feet, ÷ 27 = 2.96 cubic yards. Multiply by the weight per cubic yard of your stone to get tons.
Common questions
How many yards of gravel for a 12x20 area at 3 inches?
2.22 cubic yards, about 3.15 tons.
How many bags of gravel for a 12x20 area?
At 2 inches deep, 80 bags of 0.5 cu ft; at 4 inches, 160.
Related calculators
Sources
- https://www.engineeringtoolbox.com/dirt-mud-densities-d_1727.html
- https://hellogravel.com/guides/2025-gravel-prices-per-ton-delivered-cost-calculator-and-regional-rates/
- https://www.doitbest.com/product/276837/
- https://rochestercp.com/resources/installation-manuals/installation-manual-vintage-6.pdf