Verified Mathematical Model & Formulation
Volume (cu yd) = (Length (ft) × Width (ft) × Depth (in) / 12) / 27 × (1 + Waste% / 100) Weight (Tons) = Volume (cu yd) × Density (Tons/cu yd)
Calculates the spatial volume in cubic feet by multiplying length by width by depth (converted from inches to feet). Divides by 27 to obtain cubic yards. Multiplies by the aggregate density (standard crushed gravel is ~1.4 tons per cubic yard) and adds the contingency waste percentage.
Configurable Parameters & Standard Units
- Length: (Default: 30 ft)
- Width: (Default: 10 ft)
- Depth: (Default: 3 in)
- Waste Buffer: Recommended 5-10% for compaction (Default: 8 percent)
- Gravel Density (Tons / yd³): Standard crushed stone is 1.4 (Default: 1.4 tons_us)
Standard Worked Example & Practical Verification
Scenario: Preparing a crushed stone sub-base 40 feet long, 12 feet wide, at a depth of 4 inches with 10% waste buffer.
Practical Takeaway: Order approximately 9.5 to 10 tons from the quarry to account for minimum delivery increments and compaction settling.
Frequently Asked Questions
How deep should driveway gravel be?
For passenger cars, a total depth of 4 to 6 inches is recommended, typically installed in two layers: 3-4 inches of coarse base stone followed by 2 inches of surface gravel.
How many tons of gravel are in a cubic yard?
On average, one cubic yard of crushed gravel weighs approximately 1.4 to 1.5 US tons (2,800 to 3,000 lbs), depending on stone size, moisture content, and compaction.
Why should I include a waste factor?
A 5% to 10% waste allowance covers wheel rutting, subsoil settling, uneven ground elevations, and compaction during mechanical rolling.
Can I use metric units for this calculation?
Yes. uniqcalc automatically calculates metric equivalents (cubic meters and metric tonnes) regardless of whether you input metric or imperial units.