How much gravel you need
Gravel is ordered by volume (cubic yards) or weight (tons). Find the volume from area and depth: cubic yards = length × width × (depth in inches ÷ 12) ÷ 27. A 20 ft × 10 ft area at 4 inches deep is 200 × 0.333 ÷ 27 = about 2.47 cubic yards, which weighs roughly 3.46 tons at typical gravel density (about 1.4 tons per cubic yard). For angular base material instead, use the crushed stone calculator.
How to use this calculator
Enter the length and width of the area in feet and the depth in inches. The result shows cubic yards, an estimated tonnage, and cubic feet. For an L-shaped or irregular area, split it into rectangles, calculate each, and add them up. Work out the area first with the square footage calculator.
Recommended depth by use
The right depth depends on the job:
| Use | Typical depth |
|---|---|
| Walkway / path | 2 inches |
| Garden / decorative bed | 2–3 inches |
| Driveway (per layer) | 4 inches |
| Driveway base (total) | 8–12 inches |
Driveways are usually built in layers (sub-base, base, top), so multiply by the total depth across all layers. Deliveries are quoted by the yard, which the square feet to cubic yards calculator gives you.
Cubic yards vs. tons
Suppliers may sell by volume or weight. Conversion depends on the gravel type — this tool uses about 1.4 tons per cubic yard, a common figure for crushed stone and pea gravel. Denser or wet material weighs more; ask your supplier for the exact density of the product you're buying.
Order a little extra
Gravel compacts and settles, and some is lost to spillage and uneven ground, so add about 5–10% to your calculated amount. To budget the cost, combine the tonnage with a per-ton price; to compare project costs by area, see the price per square foot calculator. Figures here are estimates — confirm density and depth with your supplier.
Frequently asked questions
- How do I calculate how much gravel I need?
- Multiply length × width × depth (in feet) for cubic feet, then divide by 27 for cubic yards. For depth in inches, divide inches by 12 first.
- How many cubic yards is a 20x10 area at 4 inches deep?
- About 2.47 cubic yards, which is roughly 3.46 tons of typical gravel.
- How many tons are in a cubic yard of gravel?
- About 1.4 tons for common crushed stone or pea gravel, though it varies with the gravel type and moisture. Confirm with your supplier.
- How deep should gravel be for a driveway?
- A finished gravel driveway is usually 8–12 inches total, built in layers. A single top layer is often about 4 inches.
- Should I order extra gravel?
- Yes — add about 5–10% for compaction, settling and spillage so you don't run short.