The Formula
The math is three steps: find your volume in cubic feet, convert to cubic yards, then multiply by density to get tons.
A standard 2-car driveway runs about 20 ft wide × 40 ft long. At a 4-inch depth (0.333 ft), that's:
20 × 40 × 0.333 ÷ 27 = 9.9 cubic yards, or roughly 15 tons of crushed stone.
Don't want to do the arithmetic? The gravel calculator handles it instantly — including irregular shapes, cost estimates, and waste buffers.
How Deep Should the Gravel Be?
Depth is the number that changes most depending on your situation. More depth means more stability — and a bigger order.
| Use case | Recommended depth |
|---|---|
| Top-up on existing gravel | 1–2 inches |
| Footpath or light foot traffic | 2–3 inches |
| Standard driveway (single layer) | 4 inches |
| New driveway, base layer only | 4–6 inches |
| New driveway, total (base + surface) | 6–9 inches |
For a brand-new driveway on bare ground, most pros recommend two layers: a compacted base of crusher run (4–6 inches) topped with a finish layer of #57 crushed stone (2–3 inches). This costs more upfront but holds up under vehicle weight without rutting. For a simple refresh, 1–2 inches on top of the existing gravel is usually all you need.
Which Gravel Is Right for a Driveway?
Not all gravel performs equally under tire pressure. Here's what to know before you choose.
Crushed Stone (#57 Limestone or Granite)
The go-to choice for driveways. Angular edges interlock under pressure, which means the stones stay put instead of migrating to the edges. A density of about 1.6 tons per cubic yard. Best for: any driveway that sees regular vehicle traffic.
Crusher Run (Processed Gravel)
A mix of angular stone and stone dust that compacts into an almost-solid surface. Ideal for the base layer of a new driveway. Compacts so well that some people use it as the only layer. Density varies 1.4–1.6 tons/yd³.
Pea Gravel
Round, smooth, and visually attractive — but it rolls under tires and drifts to the edges without containment. Better for walkways and decorative areas. If you want the look, use it as a surface layer over a crushed stone base, with solid edging on both sides.
River Rock
Large, smooth, heavy. Beautiful for garden borders but poor for driveways — round stones don't interlock and shift badly under load. Skip it for any area that takes vehicle weight.
Cost Estimate
Gravel prices vary widely by region and material. Here's a realistic framework:
For a standard 2-car driveway (20 × 40 ft, 4-inch depth): expect 9.9 cubic yards, roughly 15 tons of crushed stone. At $30/ton plus $100 delivery, that's around $550 total — but get local quotes, because prices swing dramatically by ZIP code.
Always request at least two quotes. Price differences of 30–40% between local suppliers are common.
Before You Order — Checklist
- Add 10% for waste. Gravel settles, compacts, and some is lost to uneven ground. Order slightly more than your calculation suggests.
- Measure all irregular areas. For L-shaped or curved driveways, break the area into rectangles, calculate each, then add them up.
- Check the subgrade. Soft or clay-heavy ground benefits from a geotextile fabric layer underneath the base — it prevents the gravel from slowly sinking into the soil.
- Plan your edging. Without a border (metal, timber, or plastic), gravel migrates over time. Install edging before you pour.
- Confirm delivery access. Most trucks need space to dump or extend a chute. Ask the supplier about your specific driveway length and any overhead obstructions.
- Compact in layers. If laying more than 3–4 inches, compact each 2-inch layer with a plate compactor before adding the next. Dumping it all at once leads to soft spots.
Common questions
How much gravel for a 2-car driveway?
A typical 2-car driveway (20 × 40 ft) at 4 inches deep needs about 9.9 cubic yards or 15 tons of crushed stone. Bump that to 6 inches (new driveway base layer) and you're looking at about 14.8 cubic yards / 22 tons. Use the gravel calculator to enter your exact dimensions.
How many cubic yards is a ton of gravel?
It depends on the material. Crushed stone runs about 0.63 cubic yards per ton (1.6 tons/yd³). Pea gravel and river rock are slightly lighter — about 0.71 cubic yards per ton (1.4 tons/yd³). Your supplier may give you a more precise figure for the specific stone they carry.
One layer or two?
For a new driveway, two layers is the better long-term investment: 4–6 inches of compacted crusher run as a base, topped with 2–3 inches of #57 crushed stone as the finish surface. This costs more upfront but creates a firm, load-bearing base that won't rut. For a driveway that just needs freshening, a 1–2 inch single top-up layer works fine.
How often do gravel driveways need a refresh?
Most gravel driveways need topping up every 3–5 years. Gravel settles, compacts, and migrates to the edges over time — especially in high-traffic areas and after heavy rain. A 1–2 inch top-up typically restores the surface without full excavation.