Stone Calculator

Whether you’re building a gravel driveway, laying a garden path, or filling a French drain, guessing how much stone you need leads to wasted money or job-site delays. A stone calculator eliminates the guesswork–converting length, width, and depth into cubic yards and tons in seconds.

The calculator above handles both rectangular and circular areas. Select your stone type or enter a custom density, input the dimensions, and you’ll see exactly how many cubic yards and tons to order. Below, we break down the formulas behind the tool, share real-world examples, and provide a density table for the most common aggregates.

What Measurements Do You Need to Use a Stone Calculator?

The calculation requires only three numbers:

• Length – the longest side of the area, in feet.
• Width – the shorter side, in feet. For circular areas, input the radius instead.
• Depth – the thickness of the stone layer, in inches. Typical depths range from 2 to 6 inches depending on the project.
• Stone type – each material has a different weight per cubic yard. Select a preset or enter a custom tons-per-yard value.

For irregular-shaped spaces, break the area into a series of rectangles or circles, calculate each separately, and sum the results.

Formula for Calculating Stone Requirements

The math moves from square footage to cubic feet, then to cubic yards, and finally to tons.

Cubic feet = Length (ft) × Width (ft) × (Depth in inches ÷ 12)
Cubic yards = Cubic feet ÷ 27
Tons = Cubic yards × Stone density (tons per cubic yard)

For a circular area, the formula becomes:
Cubic feet = π × (Radius ft)² × (Depth inches ÷ 12), then continue as above.

Example Calculation for a 10 × 10 ft Patio

Imagine you’re laying a 2-inch base of crushed limestone under a patio. The area is 10 ft by 10 ft.

1. Cubic feet = 10 × 10 × (2 ÷ 12) = 16.67 ft³
2. Cubic yards = 16.67 ÷ 27 ≈ 0.62 yd³
3. Tons = 0.62 × 1.5 (density for crushed limestone) = 0.93 tons

To avoid coming up short, add 10% for compaction and uneven ground: order 1.02 tons, rounded up to the nearest quarter-ton–typically 1.25 tons from a supplier.

Stone Density Table: Tons per Cubic Yard

Density varies by material, moisture content, and quarry. Use these averages as a starting point.

If your exact material isn’t listed, ask your supplier for the loose density of the product you’re buying.

Tips for Ordering Stone

• Always order an extra 5–10% to account for compaction, settling, and irregular edges. A 4-inch layer of gravel will compact to roughly 3.5 inches after rolling.
• Check delivery minimums. Many quarries require a minimum order of 1 cubic yard or 2 tons. Small loads may incur short-load fees.
• Shape matters. Circular and irregular areas often waste more material during spreading. Calculate the circle as a square of the same diameter to get a conservative estimate.
• Consistency counts. If your project requires more than one truckload, ensure the stone comes from the same quarry batch to avoid color or sizing variations.

The tonnage calculated is an estimate based on average material density. Actual loads can differ slightly due to moisture, compaction, and segregation during transport. Confirm final quantities with your supplier before ordering.