How many tons of gravel do I need? Yards in a ton, formula and examples

Gravel is measured in cubic yards but usually sold by the ton, and that one conversion is where most driveway and path estimates go wrong. The fix is simple once you know the formula and the density of the stone you are buying. Here is how to work out how many tons of gravel you need, with worked examples for a driveway and a garden path.

Quick answer: how many yards are in a ton of gravel? About 0.7 cubic yards. Most gravel weighs 1.3–1.5 tons per cubic yard, so one ton is 0.67–0.77 cubic yards (about 18–21 cubic feet), and one cubic yard is about 1.4 tons. A single-axle dump truck carries roughly 5–7 tons and a tandem-axle truck roughly 10–15 tons, so check your supplier's load size before you book delivery.

The formula

cubic yards = length (ft) × width (ft) × depth (in) ÷ 12 ÷ 27

tons = cubic yards × density (tons per cubic yard)

Divide inches by 12 to get feet, and divide cubic feet by 27 to get cubic yards. The density depends on the material — and it is the number to confirm with your quarry or landscape yard, because it varies with the rock type, the size and how wet it is.

Typical densities

These are common planning figures, not guarantees:

• #57 stone (3/4" clean): about 1.4 tons per cubic yard
• Pea gravel: about 1.4 tons per cubic yard
• River rock: about 1.35 tons per cubic yard
• Crusher run (ABC, 21A, dense grade): about 1.5 tons per cubic yard, plus extra because it compacts

A quick rule of thumb: most gravel lands between 1.3 and 1.5 tons per cubic yard.

Example 1 — a gravel driveway

A 12 × 50 ft driveway with a 4-inch layer of #57 stone:

• 12 × 50 = 600 sq ft
• 600 × (4 ÷ 12) = 200 cu ft ÷ 27 = 7.4 cubic yards
• 7.4 × 1.4 = about 10.4 tons

If the same 4 inches were crusher run, you would order extra for compaction — dense-graded base locks together when it is rolled. With a 15% compaction allowance: 7.4 × 1.15 × 1.5 ≈ 12.8 tons. Clean stone like #57 has no fines to pack down, so it does not need that allowance.

Example 2 — a pea gravel path

A 3 ft wide, 40 ft long path at 2 inches deep:

• 3 × 40 = 120 sq ft × (2 ÷ 12) = 20 cu ft ÷ 27 = 0.74 cubic yards
• 0.74 × 1.4 = about 1 ton

How far does a ton go?

Turn the formula around: sq ft per ton = 27 ÷ density ÷ (depth in inches ÷ 12). At 1.4 tons per yard, one ton of #57 covers about 77 sq ft at 3 inches, about 116 sq ft at 2 inches and about 58 sq ft at 4 inches.

How deep should gravel be?

• Walkways and paths: 2–3 inches of decorative stone
• Driveways: built in layers — a compacted base of larger or dense-graded stone, then a top layer of #57 or similar. Many drives are 8–12 inches in total over landscape fabric, depending on the soil.
• Patio and paver base: a compacted base plus a thin bedding layer of sand

For a layered driveway, work out each layer on its own with its own density, then add them up.

Bags or bulk?

Bagged gravel is handy for small jobs, but bags are sold by weight or by fractions of a cubic foot, so the count climbs fast — 1 cubic yard is 27 cu ft, or 54 half-cubic-foot bags. Past about a cubic yard, bulk delivery is usually cheaper and far less lifting.

Our app: Gravel & Stone Calculator

Gravel & Stone Calculator is a free Android app, with a matching web version at smartgravelcalculator.com. Enter an area and depth and it shows cubic yards, tons and truckloads together, with the density row it used shown underneath — and you can edit that row to match your supplier. A driveway lift builder stacks fabric, base, middle course and top dress with per-layer tonnage. It covers #57, #8, #2 and #411 stone, crusher run, sand, pea gravel, river rock, limestone, decomposed granite, rip rap and boulders, plus paths, pads, fire-pit rings, trenches and French drains, with cost per ton or yard, delivery, labor and quotes. Every calculator is free and works offline. It is on Google Play for Android only.

Laying a new lawn next to the drive? See how much sod you need, and our deck cost guide for the patio.

Laying turf beside the gravel? How much sod do I need converts the lawn area into rolls, pallets and cost.