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How much road base do I need?
Multiply area × compacted depth for cubic yards, add extra for compaction, then multiply by about 1.5 tons per yard.
A 12 × 60 ft driveway with 6 inches of base is 360 cu ft = 13.3 yd³. With 15% for compaction at 1.5 tons per yard, that's about 23 tons of road base.
Road base tons by area and depth
At 1.5 tons per cubic yard, before compaction allowance.
| Area (sq ft) | 4 in | 6 in | 8 in |
|---|---|---|---|
| 250 | 4.63 t | 6.94 t | 9.26 t |
| 500 | 9.26 t | 13.89 t | 18.52 t |
| 720 | 13.33 t | 20.00 t | 26.67 t |
| 1,000 | 18.52 t | 27.78 t | 37.04 t |
| 2,000 | 37.04 t | 55.56 t | 74.07 t |
Build it in lifts
Spread and compact road base in layers of a few inches, dampened to help it pack. ICPI Tech Spec 2 describes compacting bases in 4 to 6 inch lifts with a plate compactor.
Building a full gravel driveway? Plan the base and top layers together.
Gravel driveway calculatorFrequently asked questions
What is road base?
A dense-graded mix of crushed stone and fines (stone dust). The fines fill the gaps so it compacts into a hard, stable layer: the usual base for gravel driveways, pads and paver driveways. It's sold as road base, crusher run, dense grade or #411 depending on the region.
How deep should road base be for a driveway?
Most residential driveway bases are 4 to 6 inches of compacted material, and more on soft or wet ground. The ICPI calls for at least 6 inches of compacted base under a paver driveway on well-drained soil.
How much does road base weigh?
Crushed stone runs 1.35 to 1.7 tons per cubic yard (Stone Center), and dense-graded base with fines sits toward the heavier end. The calculator uses 1.5 tons unless you change it.
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