A gravel driveway is only as good as its depth and its base. Too thin, and tyres rut through to the soil below; too deep, and loose stone migrates and feels unstable underfoot. This guide explains how deep a gravel driveway should be, how crushed gravel and pea gravel differ, and what drives the total cost — without pretending that prices are the same everywhere.
If you already know your driveway size, the Gravel Driveway Calculator will work out the volume for you. For a general load, see the Gravel Calculator.
How deep should a gravel driveway be?
For a driveway that carries cars regularly, a total compacted depth of about 4 inches is a common starting point, and many driveways use a layered build: a coarser base layer for drainage and load-bearing, topped with a finer, more drivable surface layer. Light-use paths can be thinner, while soft ground, heavy vehicles, or a steep slope usually call for a deeper, better-compacted base. Always confirm the build-up for your soil and expected traffic with a local supplier or contractor — depth alone does not fix poor drainage or an unprepared subgrade.
Depth also affects how the surface behaves. A thin layer over soft soil will show ruts quickly, while a very thick layer of rounded stone can shift under turning tyres. Compaction matters as much as depth: loose depth is not the same as compacted depth, so allow for settling and compaction when you order.
Worked example: a 50 ft × 12 ft driveway at 4 inches deep
Area: 50 × 12 = 600 square feet. Depth in feet: 4 ÷ 12 = 0.333 ft. Volume: 600 × 0.333 = 200 cubic feet. In cubic yards: 200 ÷ 27 = 7.41 cubic yards.
Allowing 10% for compaction, spillage, and uneven ground: 200 × 1.10 = 220 cubic feet, and 220 ÷ 27 = 8.15 cubic yards. Order about 8.15 cubic yards for this example. If your supplier sells by the ton rather than by the cubic yard, ask for that supplier’s conversion for the stone you are buying, because weight per cubic yard varies by stone type and moisture.
Volume by depth for a 600 square foot driveway
The table below shows volumes before any compaction or waste allowance.
| Depth | Volume (cubic feet) | Volume (cubic yards) |
|---|---|---|
| 3 in | 150.0 | 5.56 |
| 4 in | 200.0 | 7.41 |
| 6 in | 300.0 | 11.11 |
Crushed gravel vs. pea gravel
Crushed gravel has angular faces that lock together when compacted, which is why it is the usual choice for a driving surface: it stays in place better, sheds water, and supports weight. Pea gravel is rounded, smooth, and comfortable to walk on, but those same rounded stones shift under tyres and can migrate off the driveway. Pea gravel suits paths, patios, and decorative areas far better than a main driving lane.
For pea gravel quantities on a path or decorative area, use the Pea Gravel Calculator. For borders, beds, and landscaping stone around a driveway, the Decorative Rock Calculator can help you size that separate area — do not count decorative stone as part of the driving surface depth.
What drives gravel driveway cost?
Cost is driven mainly by volume, stone type, delivery distance, and site preparation. A deeper driveway, a longer or wider area, and a site that needs grading, edging, or a new base will all cost more. Delivery charges, minimum loads, and spreading or compacting labour are separate from the price of the stone itself, so a quote that only lists the stone price is incomplete. Prices vary by region and supplier, so use calculator results as an estimate to compare with local quotes, not as a fixed price.
Check your numbers
- Gravel Driveway Calculator — volume and cost factors for a driveway.
- Gravel Calculator — volume for a general gravel area.
- Pea Gravel Calculator — quantities for paths and decorative areas.
- Decorative Rock Calculator — quantities for decorative stone.
Frequently asked questions
How deep should a gravel driveway be?
About 4 inches of compacted depth is a common starting point for a car driveway, often built as a coarser base plus a finer surface layer. Soft ground, heavy vehicles, or steep slopes may need a deeper build-up.
Is pea gravel good for a driveway?
Pea gravel is not the best choice for a main driving surface because its rounded stones shift under tyres. It works well for paths and decorative areas. Crushed, angular gravel locks together better for driving.
How much gravel do I need for a 50 ft × 12 ft driveway?
At 4 inches deep, the volume is 200 cubic feet, or 7.41 cubic yards before any allowance. With a 10% allowance for compaction and waste, order about 8.15 cubic yards.
Why does gravel driveway cost vary so much?
Volume, stone type, delivery distance, grading and edging work, and spreading labour all affect the total. Prices vary by region, so compare a calculator estimate with local supplier quotes.