Gravel Driveway Depth Calculator
This gravel driveway depth calculator shows how much gravel your driveway needs at 2, 4, 6 and 8 inches deep (5, 10, 15 and 20 cm in metric), side by side, in cubic yards and tons. The allowance and density are editable, so you can compare depths with your own material.
Depth comparison calculator
Results
Results appear here as you type.
How depth changes the amount you need
Volume rises in direct proportion to depth: doubling the depth doubles the gravel. For a 60 × 12 ft driveway with crushed stone and a 10% allowance:
| Depth | Volume with 10% allowance | Weight | Order |
|---|---|---|---|
| 2 in | 4.89 yd³ | 6.84 tons | 7 tons |
| 4 in | 9.78 yd³ | 13.69 tons | 14 tons |
| 6 in | 14.67 yd³ | 20.53 tons | 21 tons |
| 8 in | 19.56 yd³ | 27.38 tons | 28 tons |
The calculator starts with a 10% allowance and the 1.40 tons per cubic yard planning density for crushed stone. Change either and every depth is recalculated with the same values, so the comparison stays like for like.
Choosing a depth
The calculator compares quantities; it cannot tell you which depth your driveway needs. That depends on your soil, drainage, climate and traffic. Common planning starting points are:
- About 2 inches: a top-up over a firm, existing gravel base.
- 3 to 4 inches: resurfacing a worn drive for cars.
- 6 inches or more, in two layers: a new drive, usually a compacted base with a surface layer on top.
- Deeper: heavy vehicles or soft, wet ground, where a contractor’s advice matters most.
The gravel driveway depth guide explains the layers and the limits of these ranges. To size a base layer and landscape fabric separately, use the driveway base gravel calculator.
Related calculators
- Price the depth you choose with the gravel driveway cost calculator.
- For a single depth with cost and two-layer mode, use the gravel driveway calculator.
Frequently asked questions
Can a gravel layer be too deep?
Yes, for the surface layer. A thick layer of loose stone that is not locked together, especially rounded stone like pea gravel, can shift under tyres. That is why new drives are usually built as a compacted base under a thinner surface layer.
How much does gravel compress after rolling?
It depends on the material, its moisture and the equipment, so ask your supplier or contractor for their figure. As arithmetic only: if a 6 inch loose layer settled by 10%, it would finish at 5.4 inches; at 20%, 4.8 inches. Set the allowance in the calculator to suit the figure you are given.
Can I compare other depths?
The comparison uses four fixed depths. For any other depth, enter it in the gravel driveway calculator.