Quick answer
To calculate yards of gravel: cubic yards = length × width × depth (ft) ÷ 27, or sq ft × depth (inches) ÷ 324. A 20 × 10 driveway at 4 inches needs 2.47 cubic yards. Run it in the free gravel calculator.
How to calculate yards of gravel (formula)
Cubic yards = Length (ft) × Width (ft) × Depth (ft) ÷ 27
Depth in inches ÷ 12 first. Shortcut when you already know square footage:
Cubic yards = Square feet × Depth (inches) ÷ 324
“Yards of gravel” almost always means cubic yards, not square yards. Square yards measure area only.
Step-by-step: calculate gravel yardage
- Measure length and width in feet (or start from known square feet).
- Choose depth in inches (paths 2–3 in; driveway base 4–6 in compacted).
- Convert depth to feet (÷12) or use the ÷324 shortcut.
- Divide by 27 for cubic yards.
- Add 10–15% waste (25–30% for heavily compacted driveway bases).
Worked example: 40 × 12 driveway at 4 inches.
- Area: 480 sq ft
- Cubic yards: 480 × 4 ÷ 324 = 5.93 cu yd
- With 15% waste: ≈ 6.8 cu yd to order
- At 1.35 tons/cu yd (#57): ≈ 8.0 US tons before waste
Gravel calculator yards — coverage table
| Depth | Sq ft per cubic yard | Cu yd per 100 sq ft |
|---|---|---|
| 1 in | 324 | 0.31 |
| 2 in | 162 | 0.62 |
| 3 in | 108 | 0.93 |
| 4 in | 81 | 1.23 |
| 6 in | 54 | 1.85 |
For general volume without gravel density, use the cubic yard calculator. Convert area with square feet to cubic yards.
Convert gravel yards to tons
Many quarries sell by the ton. After you calculate cubic yards:
US tons = Cubic yards × Density (tons per cu yd)
| Material | US tons / cu yd | Example: 3 cu yd |
|---|---|---|
| Pea gravel | 1.40 | 4.2 tons |
| #57 crushed stone | 1.35 | 4.05 tons |
| River rock | 1.25 | 3.75 tons |
| Crusher run / dense grade | 1.45–1.50 | ~4.4 tons |
Confirm density with your supplier, then use cubic yards to tons.
How to calculate cubic yards for gravel driveways
Driveway yardage should be layered: compacted base first, then a thinner surface. Loose stone settles ~20%, so order extra for the base. Full build notes: gravel driveway guide. Quantity overview: how much gravel do I need. Pea gravel vs #57: pea gravel calculator guide.