How much gravel for a driveway

Measure the driveway, apron included

Take the length along the middle of the drive from the street edge to the garage or parking pad, and the width at two or three points; if it varies, use the average. A single-car drive is usually 10–12 ft wide, a double 20–24 ft.

Most driveways widen at the street or flare in front of the garage. Measure that apron as its own rectangle and run the sheet a second time for it, or add the areas with the square footage calculator. A curved drive is measured the same way: the length along the centerline and the average width.

Two layers, two runs of the sheet

The base course carries the load: 4–6 in of compacted crushed stone, usually a dense-graded mix up to 1½ in with fines. Four inches is enough on firm, well-drained soil; go to 6 in on clay or where trucks turn. The top course is 2–3 in of finer stone, ¾ in crushed or crusher run, that packs into a surface.

The calculator works one layer at a time, so run it twice: once at the base depth, once at the top course depth. Order them separately; they are different products at different prices per yard.

Buy crushed, angular stone for both. The broken faces lock together under compaction. Round pea gravel and river rock roll under tires, migrate to the edges and never firm up; they belong on a path or in a bed.

How to measure and order

1. Measure the length along the center and the width at two or three points; average the widths.
2. Measure any apron or turnaround as a separate rectangle.
3. Type the length and width with the base depth (4–6 in) and read the cubic yards.
4. Change the depth to the top course (2–3 in) and read the second figure.
5. Ask the yard whether they sell by the cubic yard or the ton; the sheet shows both at 1.4 tons per cubic yard, and you can change the density to the supplier’s figure.
6. Order each product with the sheet’s settling allowance included, and book delivery for a day you can spread it.

Compact in lifts, crown the surface, hold the edges

Spread the base in lifts of 2–3 in and run a plate compactor over each before adding the next. One 6 in lift compacted from the top stays loose underneath and shows up later as ruts. Damp stone compacts better than dry.

Crown the top course, higher in the middle than at the edges by about ¼ in per foot of half-width, so a 12 ft drive sits roughly 1½ in higher at the center and water runs off instead of soaking the base. On a slope, cut a shallow swale across the low end so water leaves the surface.

Edging keeps the stone where you put it. Timber, steel edging or a concrete curb along both sides stops the top course spreading into the lawn every time a tire rides the edge. Set it before the top course so you can screed against it.

Cubic yards, tons and the truck

Suppliers quote by the cubic yard or the ton. The sheet converts at 1.4 tons per cubic yard, the usual planning figure for dry crushed stone; wet material weighs more. A tandem dump truck carries 10–14 cu yd. A full-size pickup holds about 2 cu yd level, but that much crushed stone weighs close to 3 tons, more than a half-ton truck is rated for. For anything beyond a small repair, have it delivered.

Common mistakes

• Laying 3 in of ¾ in stone straight on soil with no base. It sinks within a season and you buy it again.
• One thick lift instead of several thin ones. The top looks compacted; the bottom isn’t.
• Pea gravel or river rock on the driving surface. It rolls, ruts and ends up in the grass.
• Building it flat. Without a crown the water stays on the drive and works into the base.
• Ordering from one run of the sheet. The base and the top course are two orders.