How this road base calculator works
Base course is bought loose but specified compacted, so the density and the allowance both matter more than usual:
tons = yd³ × 1.5 × (1 + allowance%) → rounded up to ¼ ton
Worked example: base for a 50 × 12 gravel driveway
600 ft² at 6 in compacted is 300 ft³ — 11.1 yd³, or 16.7 tons of dense-grade. Add the 10% compaction allowance and the scale order is 18.5 tons, about $648 at $35 a ton. One ton covers 36 ft² at this depth.
How many tons of road base for a driveway?
| Driveway | Order |
|---|---|
| 40 × 10 ft | 12.25 t |
| 50 × 12 ft | 18.5 t |
| 100 × 12 ft | 36.75 t |
| 150 × 12 ft | 55 t |
| Lift | Material & depth |
|---|---|
| Subbase | #3 stone, 4–6″ (soft ground) |
| Base | Crusher run / CA-6, 4″ |
| Top | #57 clean stone, 2–3″ |
Road base FAQ
How much road base do I need for a driveway?
A new 50 × 12 ft gravel driveway at 6 in compacted takes 11.1 yd³ — 16.7 tons of dense-grade base, ordered as 18.5 tons with the 10% compaction allowance, about $648 at $35 a ton. Scale the dimensions above to your drive.
How many tons of road base are in a cubic yard?
About 1.5 tons compacted in place — the fines pack the voids solid, which is the whole point of dense-grade. Loose in the truck it runs nearer 1.4; the calculator carries both figures so you can price either way.
How deep should road base be?
6–8 inches compacted for a residential gravel driveway on decent ground, 8–12 over soft or clay subgrade, placed in 3–4 in compacted lifts. Under concrete or pavers, 4–6 in usually does; under asphalt plan 6–8.
What is the difference between road base and gravel?
Road base is crushed stone WITH the fines left in — sizes from dust up to ¾ or 1½ in — so it locks into a hard, almost pavement-like mat. Clean gravel like #57 has no fines, stays loose and drains; it tops the base rather than replacing it.
How much does a ton of road base cover?
About 36 ft² at 6 in compacted — 54 ft² at 4 in, 27 at 8 in. Road base goes fast: a single car-width drive eats a ton roughly every 9 feet at full depth.
How much does road base cost?
Typically $25–45 per ton in 2026 — one of the cheapest materials a quarry sells — plus delivery. The default driveway is about $648 in stone; spreading and plate-compacting it is where the weekend goes.
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