Multiply lane length × width in feet by depth in feet, divide by 27 for cubic yards, then multiply by 1.55 for tons of crusher run. A 200-ft lane 10 ft wide at 8 inches deep needs about 49 cubic yards, or 77 tons — order close to 88 tons with 15% compaction allowance.
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Order – tons (includes your waste allowance) so compaction and spillage don’t leave you short.
Road Base Calculator Guide
A farm lane or private road is a driveway at scale, and scale changes the game: hundreds of feet of length turn every inch of depth into truckloads. At 8 inches deep, a 12-foot-wide lane consumes roughly 46 tons of crusher run per 100 feet — so a quarter-mile drive is a 600-ton project. This calculator does that multiplication honestly, at 1.55 tons per cubic yard with a 15% compaction allowance.
Because tonnage is so sensitive to depth, resist the temptation to shave an inch to save money. An under-built lane fails in the wheel tracks within a wet season, and rebuilding costs more than building right once.
How Many Tons of Road Base Does 100 Feet of Lane Take?
| Lane width | Depth | Per 100 ft (yd³) | Per 100 ft (tons) |
|---|---|---|---|
| 10 ft | 6 in | 18.5 | 28.7 |
| 10 ft | 8 in | 24.7 | 38.3 |
| 12 ft | 8 in | 29.6 | 45.9 |
| 12 ft | 10 in | 37.0 | 57.4 |
Six inches suits car-only lanes on firm ground; 8 inches is the sensible default where pickups, deliveries, and tractors run; 10 or more belongs on soft subgrade or routes that see loaded trucks. Figures are before the 15% allowance the calculator adds.
Lifts, Fabric, and Crown — the Three Rules of Lane Building
- Geotextile first on soft ground. A woven stabilization fabric between subgrade and stone stops the base from punching into mud — on wet clay it can save 2–3 inches of stone across the whole lane, which pays for the fabric several times over.
- Build in 3–4 inch lifts. Compaction equipment only densifies the top few inches, so an 8-inch base goes down as two compacted lifts, never one loose dump.
- Crown 2–4%. Shape the centerline a quarter to a half inch higher per foot of half-width so water runs off sideways. Standing water is the origin story of every pothole.
Maintain the lane by re-grading annually and keeping ditches open at the edges; drainage does more for longevity than fresh stone does. For material specifics on the default base grade, see the crusher run calculator, and to price the whole tonnage before committing, run it through the gravel driveway cost calculator.
Frequently Asked Questions
How thick should a gravel road base be?
Private lanes carrying cars need 6–8 inches of compacted base; anything seeing trucks, tractors, or deliveries should get 8–12 inches. On soft or wet subgrade, add geotextile fabric first — it can save several inches of stone that would otherwise punch into the mud.
How many tons of road base per 100 feet of lane?
A 10-ft-wide lane at 8 inches deep takes about 24.7 cubic yards, or 38 tons of crusher run, per 100 feet before waste. Widen to 12 feet and the same stretch needs roughly 46 tons.
Should road base be installed in lifts?
Yes — spread and compact in lifts of 3–4 inches rather than tipping the full depth at once. A plate compactor or roller only densifies the top few inches, so a single thick lift stays soft underneath and ruts within a season.
What is the crown on a gravel road?
The crown is the raised centerline that sheds water to both edges — aim for about 2–4%, which is roughly a quarter to a half inch of fall per foot of half-width. A flat lane holds puddles, and puddles are where potholes start.