How Much Gravel for a Gravel Road? (Tons per Mile Chart)
A 12 ft wide gravel road with 4 inches of stone needs about 782 cubic yards, or roughly 1,095 tons, per mile. That works out to about 21 tons for every 100 feet. A new road built from scratch needs more, because it has a thick base layer under the top stone. The gravel calculator gives cubic yards and tons for any length, width and depth.
The formula
cubic yards = length (ft) × width (ft) × depth (in) ÷ 12 ÷ 27
tons = cubic yards × 1.4 (typical for gravel)
One mile is 5,280 feet. The 1.4 tons per cubic yard figure is an average for crushed gravel; ask your quarry for the weight of the exact product you're buying.
Gravel per mile of road
| Road width | 4 in deep | 6 in deep |
|---|---|---|
| 10 ft | 652 yd / 913 tons | 978 yd / 1,369 tons |
| 12 ft | 782 yd / 1,095 tons | 1,173 yd / 1,643 tons |
| 16 ft | 1,043 yd / 1,460 tons | 1,564 yd / 2,190 tons |
| 20 ft | 1,304 yd / 1,825 tons | 1,956 yd / 2,738 tons |
Gravel per 100 feet of road
| Road width | 4 in deep | 6 in deep |
|---|---|---|
| 10 ft | 12.3 yd / 17.3 tons | 18.5 yd / 25.9 tons |
| 12 ft | 14.8 yd / 20.7 tons | 22.2 yd / 31.1 tons |
| 16 ft | 19.8 yd / 27.7 tons | 29.6 yd / 41.5 tons |
These figures are loose stone before compaction. Add 10–20% to allow for the stone settling once it's rolled and driven on.
How deep should a gravel road be?
| Layer | Typical stone | Depth |
|---|---|---|
| Base | Large crushed stone (often sold as #3 or 1.5–2.5 inch) | 6–8 in, more on soft ground |
| Surface | Crusher run / dense grade (stone mixed with fines so it packs hard) | 3–4 in |
| Top-up | Same surface stone | 1–2 in every few years |
A lane that only sees cars can get by with a thinner base on firm soil. Roads that carry trucks, farm equipment or delivery vehicles need the thicker base. Product names vary by region, so describe the stone size to your supplier.
Worked example: quarter-mile lane, 12 ft wide
- Length: a quarter mile is 1,320 ft.
- Base, 6 in: 1,320 × 12 × 6 ÷ 12 ÷ 27 = 293 cubic yards ≈ 411 tons
- Surface, 3 in: 1,320 × 12 × 3 ÷ 12 ÷ 27 = 147 cubic yards ≈ 205 tons
- Total: about 616 tons; with 15% for compaction, about 710 tons
A standard dump truck carries roughly 10–15 tons, so a job this size is around 48–71 loads. Ask about delivery fees per load and whether the driver can spread the stone as they tip ("tailgate spreading"), which saves a lot of work.
Tips for a road that lasts
- Strip the topsoil down to firm subsoil and lay woven geotextile fabric so the base stone doesn't sink into the mud.
- Crown the road so the middle sits higher than the edges. A slope of about half an inch per foot of width lets rain run off instead of making potholes.
- Dig ditches along the sides on sloped or wet ground so water has somewhere to go.
- Compact each layer with a roller or plate compactor before adding the next one.
For a single driveway rather than a long road, see how much gravel for a driveway. To convert between tons and yards for other materials, see how much a yard of gravel weighs.