Gravel suppliers price and deliver material by the ton, not the cubic yard — so converting your project’s dimensions into an actual order quantity requires one extra step most calculators skip. Our gravel calculator handles the full chain: area → cubic feet → cubic yards → tons.
The calculation
Area = length × width
Cubic feet = area × (depth in inches ÷ 12)
Cubic yards = cubic feet ÷ 27
Tons = cubic yards × density (tons per cubic yard)Example
A 20ft × 10ft driveway section, 4 inches deep, at 1.4 tons/cubic yard (a typical crushed stone density):
- Area: 200 sq ft
- Cubic feet: 200 × (4/12) = 66.7 cu ft
- Cubic yards: 66.7 ÷ 27 = 2.47 cu yd
- Tons needed: 2.47 × 1.4 = 3.46 tons
Why density is adjustable
Gravel, crushed stone, and decorative aggregate products vary in how densely they pack — most fall in the 1.3-1.5 tons per cubic yard range, but the exact figure depends on stone size and type. Ask your supplier for their specific product’s density (often listed on their pricing sheet) rather than relying on a generic default for a large order.
How deep should you go?
A load-bearing driveway typically needs 4-6 inches of base material (sometimes with additional compacted sub-base beneath for vehicle traffic), while a simple garden path might only need 2-3 inches. Match your depth input to your project type.
Many contractors order 5-10% extra beyond the calculated volume to account for compaction settling — consider rounding your final order up a bit for a real-world project.