AcreRulerWhy compaction matters
Gravel is sold loose, but once it's spread and compacted it takes up less space. If you order only the compacted volume you'll come up short, which is a common complaint about basic calculators. Crushed stone base typically compacts 15 to 25%.
The formula
- Compacted volume (cu yd) = area (sq ft) × depth (in) ÷ 12 ÷ 27
- Order volume = compacted volume × (1 + compaction %) × (1 + waste %)
- Tons = order volume × density (about 1.4 tons per cu yd for crushed stone; 1.3 to 1.5 for most gravel)
Example
A 12 × 50 ft driveway (600 sq ft) at 4 in deep is 7.41 cu yd compacted. With 15% compaction and 5% waste, order 8.94 cu yd, or about 12.5 tons.
Typical depths
| Use | Depth |
|---|---|
| Walkway | 2–3 in |
| Patio or shed base | 4 in |
| Driveway | 4–6 in (plus 4–8 in sub-base on soft ground) |
FAQ
How many tons of gravel in a cubic yard?
About 1.4 tons for crushed stone. Pea gravel is about 1.3 and wet or dense stone can reach 1.5.
What compaction % should I use?
15% is a safe default for crushed stone base; use 20 to 25% for deep driveway base that will be plate-compacted.