How deep should driveway gravel be?

A driveway needs at least 6 inches of gravel total: a 4-inch base layer of large angular stone for structural support, topped with 2 inches of smaller surface gravel. For heavy vehicle traffic, increase the base to 6 inches for a total of 8 inches.

What type of gravel is best for a driveway?

Crushed stone (#57 stone or 3/4-inch crushed) is the best surface layer for most driveways. It's angular, so it locks together and compacts under traffic rather than rolling away. Use #411 crusher run or bank gravel for the base layer under the surface stone.

How much does gravel cost per ton?

Crushed stone typically costs $20–50 per ton depending on type and region. Delivery adds $50–150 per load. Most deliveries carry 14–20 tons per truckload. Smaller quantity deliveries cost more per ton. Buying during off-season (late fall or winter) sometimes yields lower prices.

How long does a gravel driveway last?

A well-installed gravel driveway with proper base preparation and drainage lasts 10–20 years before major renovation. However, it requires top-up every 3–5 years as gravel is displaced by traffic and compacts over time. Annual raking to fill ruts extends the life significantly.

Do I need a base layer under driveway gravel?

Yes. A base layer of larger angular stone (4–6 inches deep) is critical for a stable driveway. Skipping the base causes the surface gravel to sink into soft soil, creating ruts and muddy spots. Installing geotextile fabric between native soil and the base layer further prevents gravel migration.

How Much Gravel Do You Need for a Driveway? Complete Guide

Calculating Gravel for a Driveway

Gravel is sold by the ton or cubic yard. The calculation starts the same as any volume project: length × width × depth ÷ 27 = cubic yards. To convert to tons, multiply cubic yards by approximately 1.4 tons per cubic yard (the weight varies slightly by gravel type — crushed stone is slightly heavier than pea gravel).

Example: A 10 ft × 100 ft driveway at 6 inches deep: 10 × 100 × 0.5 ÷ 27 = 18.5 cubic yards × 1.4 = 25.9 tons.

Recommended Depths for Driveway Gravel

A properly built gravel driveway uses two layers for stability and drainage:

Base layer (4 inches): Use larger, angular crushed stone (#57 or #411 stone, 1–2 inch pieces). This layer provides structural support and allows water to drain through.
Surface layer (2 inches): Use smaller, compactable gravel (3/4 inch crushed stone or crusher run). This creates a stable driving surface that compacts well.

Total recommended depth: 6 inches minimum. In areas with heavy vehicles (trucks, RVs), increase the base layer to 6 inches for a total depth of 8 inches.

Gravel Types for Driveways

Crushed stone (#57 stone): 3/4 inch angular pieces. Excellent drainage, packs well, resists rutting. Most popular choice for driveway surfaces. $30–50 per ton.
#411 crusher run: Mix of crushed stone and stone dust. Compacts very firmly, ideal for base layers or rural driveways. $20–35 per ton.
Pea gravel: Small rounded stones, 3/8 inch. Attractive appearance but rolls underfoot and under tires, doesn't compact. Better for walkways than driveways. $25–45 per ton.
Caliche (base rock): Native limestone aggregate common in southwestern US. Inexpensive, compacts well. $10–20 per ton locally.
River rock: Smooth rounded stones. Decorative only — too unstable for driveways. Not recommended.

Compaction Factor

Angular crushed stone compacts under traffic and time. When ordering, add a 10–15% compaction factor to your calculated volume so your finished depth meets the target. Compaction is most pronounced in the first year of use. After initial settling, gravel driveways are typically topped up every 3–5 years.

Drainage and Edge Restraints

Proper drainage is critical for a gravel driveway's longevity. The driveway surface should crown slightly in the center (1/4 inch per foot of width) so water runs to the sides rather than pooling and softening the base. Install drainage ditches or culverts at low points.

Edge restraints — metal, plastic, concrete, or natural stone borders — prevent gravel from spreading onto lawns. They are especially important on flat terrain. Budget $1–3 per linear foot for metal edging or $2–5 per linear foot for concrete curbing.

Cost Breakdown

For a typical 12 ft × 50 ft driveway (basic residential single-car):

Base layer (4 inches, #411): 7.4 yards × 1.4 = 10.4 tons at $30 = $312
Surface layer (2 inches, #57): 3.7 yards × 1.4 = 5.2 tons at $40 = $208
Delivery: $50–100 per load (one load typically handles up to 15 tons)
Labor for grading and spreading: $200–500 for a contractor

Total estimated material cost: $600–1,200 for a basic 600 sq ft driveway depending on region and gravel type.

Gravel Driveway Lifespan and Maintenance

A properly installed gravel driveway can last 10–20+ years with periodic top-ups. Annual maintenance includes raking ruts, redistributing displaced gravel, and adding 1–2 tons of surface gravel every few years. Installing a geotextile fabric between the soil and base layer significantly reduces gravel sinking into the soil over time.