How the Stone Calculator Works

Every estimate this calculator produces comes from the same three-step math that quarries and landscape suppliers use, applied with accurate material densities. Understanding it takes thirty seconds and means you can sanity-check any quote a supplier gives you.

Step 1 — Volume in cubic feet

Length (ft) × Width (ft) × Depth (ft). Depth is almost always measured in inches on site, so divide inches by 12 first — a 3-inch layer is 0.25 feet. For circular areas, the calculator uses π × radius² instead of length × width.

Step 2 — Convert to cubic yards

Cubic feet ÷ 27. There are 27 cubic feet in a cubic yard, and the cubic yard is the standard volume unit bulk material is discussed in across the US.

Step 3 — Convert to tons

Cubic yards × material density. This is where material choice matters: a cubic yard of crushed stone weighs about 1.5 tons, pea gravel 1.35 tons, and lightweight lava rock only 0.65 tons. Suppliers sell by weight, so this conversion is what turns your measurements into an order.

Material Densities at a Glance

Material	Tons per yd³	1 ton covers (at 3 in deep)
Crushed stone	1.50	≈ 72 sq ft
#57 stone	1.45	≈ 74 sq ft
Crusher run / DGA	1.55	≈ 70 sq ft
Gravel	1.40	≈ 77 sq ft
Pea gravel	1.35	≈ 80 sq ft
River rock	1.50	≈ 72 sq ft
Sand	1.50	≈ 72 sq ft
Topsoil / fill dirt	1.10	≈ 98 sq ft

Densities vary a little with moisture and source quarry — when your supplier publishes their own density figure, prefer it. The values above are the industry-standard mid-range figures used across supplier calculators.

Recommended Depths for Common Projects

• Driveways: 4–6 inches of compacted material — a crusher run base topped with clean #57 stone is the classic build.
• Walkways and paths: 2–3 inches over firm ground gives a stable, comfortable surface.
• Decorative beds and borders: 1–2 inches is enough for ground cover that suppresses weeds.
• Patio bases: 4 inches of compacted base plus 1 inch of bedding sand under pavers.
• French drains: surround the pipe with 3+ inches of clean washed stone on all sides.

Order the Right Amount the First Time

The single most expensive mistake in stone ordering is not over-buying — it’s under-buying. A second delivery of half a ton carries the same delivery fee as the first ten tons. That’s why every estimate here includes a configurable waste allowance (default 10%) covering compaction, settling into soil, and handling losses. For compacted base layers like crusher run, raise it to 15%.

Need a material-specific tool? Browse all of our stone and gravel calculators — from the crushed stone calculator and gravel calculator to project planners like the gravel driveway calculator and paver base calculator.

Explore All 70+ Calculators

Every tool is free, instant, and tuned to its material’s real density — pick the category that matches your project.

Frequently Asked Questions

Do you buy stone by the yard or by the ton?

Most bulk suppliers sell stone by the ton, but you plan projects by volume. This calculator converts your cubic yards into tons using the density of the material you pick, so the number you order matches the number you measured.

How many tons of stone are in a cubic yard?

Most crushed stone and gravel weighs 1.4 to 1.6 US tons per cubic yard. Lighter materials like lava rock are around 0.65 tons, while dense riprap can reach 1.65 tons per cubic yard.

How much stone do I need for 100 square feet?

At a typical 3-inch depth, 100 square feet needs 25 cubic feet, which is 0.93 cubic yards or roughly 1.4 tons of crushed stone. Double the depth and you double the amount.

Why should I add a waste allowance?

Stone compacts when tamped, settles into soil, and some is always lost in handling. Ordering 5–10% extra avoids paying a second delivery fee for a small top-up load, which usually costs far more than the extra material.