# How much stone or gravel do I need?

Computes the tons and cubic yards of gravel, crushed stone or base material for an area at a chosen depth, with a waste allowance, and the cost per ton.

- Page: https://www.acalculator.org/construction/stone-calculator
- JSON spec: https://www.acalculator.org/construction/stone-calculator.json
- Version: 26e3b9269b9b

## Default answer

Example with the default inputs (Area shape Rectangle, Length (diameter for a circle, base for a triangle) 10 ft, Width (height for a triangle) 10 ft, Depth 3 in, Material category Decorative gravel, Material Pea gravel, Waste allowance 10%): 100 ft² of stone at 3 in deep needs 1.44 tons with the waste allowance.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| shape | Area shape | The shape of the area: a rectangle, a circle, or a triangle. |
| len | Length (diameter for a circle, base for a triangle) | The length of a rectangle, the diameter of a circle, or the base of a triangle. |
| wid | Width (height for a triangle) | The width of a rectangle, or the height of a triangle measured square to its base. |
| dep | Depth | How thick the layer of stone is. |
| materialCategory | Material category | The kind of material: decorative gravel, crushed stone, or base material. |
| materialType | Material | The decorative gravel. |
| crushed | Material | The crushed stone. |
| base | Material | The base material. |
| density | Material density | The weight of one cubic foot of the material. Leave empty to use the typical density of the chosen material. |
| wasteFactor | Waste allowance | Extra material for spills and uneven ground, as a percent of the volume. |
| price | Price per ton | The price of one US ton (2,000 lb) of the material. Leave empty to skip the cost. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| tons | Stone to order | The weight to order in US short tons, waste included: volume × (1 + waste ÷ 100) × density. |
| tonnes | Metric tonnes | The weight to order in metric tonnes (1,000 kg). |
| cubicYards | Volume to order | The volume to order, waste included, in cubic yards. |
| area | Area | The area of the shape. |
| coverage | Coverage per ton | The area one US ton covers at this depth, before the waste allowance. |
| densityUsed | Density used | The material density used for the weight. |
| cost | Estimated cost | The weight to order in US tons × the price per ton. |

## Method

tons = area × depth × (1 + waste ÷ 100) × density ÷ 2,000 lb

## Assumptions

- Rectangle: length × width. Circle: π × diameter² ÷ 4. Triangle: base × height ÷ 2.
- The density is the typical loose, dry bulk density of the chosen material unless you type your own. Wet or compacted stone weighs more.
- Tons are US short tons of 2,000 lb; tonnes are metric tonnes of 1,000 kg.
- Coverage per ton is 2,000 lb ÷ (depth × density), before the waste allowance.

## Worked examples

1. shape = rectangle, len = 3.048, wid = 3.048, dep = 0.0762, materialCategory = decorative-gravel, materialType = pea-gravel, wasteFactor = 10%, price = $35.00 gives tons = 1,309.747968, cost = $50.53, coverage = 7.078327. Source: Engineering ToolBox, Dirt and Mud - Densities (gravel, dry 105 lb/ft³). https://www.engineeringtoolbox.com/dirt-mud-densities-d_1727.html.
2. shape = rectangle, len = 6.096, wid = 3.048, dep = 0.1016, materialCategory = crushed-stone, crushed = crushed-limestone-57, wasteFactor = 0% gives tons = 2,721.55422, cubicYards = 1.88779. Source: Engineering ToolBox, Dirt and Mud - Densities (gravel, dry 105 lb/ft³). https://www.engineeringtoolbox.com/dirt-mud-densities-d_1727.html.
3. shape = circle, len = 3.048, dep = 0.0508, materialCategory = decorative-gravel, materialType = lava-rock-red, wasteFactor = 0% gives area = 7.296588, tons = 252.344185. Source: Engineering ToolBox, Dirt and Mud - Densities (gravel, dry 105 lb/ft³). https://www.engineeringtoolbox.com/dirt-mud-densities-d_1727.html.
4. shape = triangle, len = 4, wid = 3, dep = 0.1, materialCategory = base-material, base = road-base, density = 1,800, wasteFactor = 5% gives area = 6, tonnes = 1,134. Source: Engineering ToolBox, Dirt and Mud - Densities (gravel, dry 105 lb/ft³). https://www.engineeringtoolbox.com/dirt-mud-densities-d_1727.html.

## FAQ

### How does the stone calculator work?

The stone calculator works out the area of your project space, multiplies it by the depth to get the volume, adds a waste allowance, and converts the volume to weight with the density of the material you choose. For example, a 10 ft × 10 ft bed of pea gravel 3 inches deep with 10% extra is 27.5 cubic feet, which at 105 lb per cubic foot is 2,887.5 lb, or 1.44 tons.

### What types of projects can I calculate with this tool?

This calculator handles a wide range of landscaping and construction projects including ground cover and decorative beds, pathways and patios, driveways, paver bases, and other areas filled with loose stone. Pick the depth your project needs.

### How accurate are the calculations?

The volume is exact for the dimensions you enter. The weight depends on the density, which varies with the stone, its size, its moisture, and how tightly it is packed. The calculator uses typical loose, dry densities; for large orders, ask your supplier for the weight per cubic yard of their material and type it in.

### What is a waste factor and why is it important?

A waste factor accounts for material that gets lost during installation due to spillage, uneven ground, cutting, and shaping. Many professionals add about 10% extra material to avoid running short. The calculator adds this allowance to the volume and weight to order.

### How do I choose the right material for my project?

Material selection depends on your project type, budget, and aesthetic preferences. Decorative gravels like pea gravel and river rock are common for pathways and garden beds. Crushed stone works well for driveways and bases. Base materials like road base provide foundation support. Consider drainage needs, traffic load, and maintenance when making your selection.

### What's the difference between bulk and bagged materials?

Bulk materials are sold by the ton or cubic yard and delivered in large quantities, making them more cost-effective for larger projects. Bagged materials come in smaller quantities (typically 0.5 cubic feet) and are convenient for smaller projects or areas with limited access.

### How do I measure irregularly shaped areas?

For irregular shapes, break your area into smaller, manageable shapes like rectangles, triangles, or circles. Calculate each section separately and add the results together.

### What depth should I use for different project types?

Common depths are 2-3 inches for pathways, at least 3 inches for decorative beds, and 4-6 inches for driveways and paver bases. Check the product and local guidance for your project.

### How do I convert between different units of measurement?

You can enter each dimension in feet, inches, yards, meters, or centimeters, and pick the unit next to each box. The calculator converts everything exactly before it multiplies.

### What is material density and why does it matter?

Material density is how much a material weighs per unit volume (typically pounds per cubic foot). Different stone types have different densities - for example, lava rock is much lighter than crushed limestone. The calculator uses the density to convert volume to weight.

### Can I use this calculator for flagstone or wall stone projects?

This calculator is for loose materials like gravel, crushed stone, and aggregates. Flagstone and wall stone are usually sold by the area they cover rather than by volume, so ask your supplier for their coverage per ton.

### What should I do if my calculations seem too high or low?

Double-check your measurements and ensure you're using the correct units. Check that the depth is in inches, not feet: 3 feet of gravel is twelve times as much as 3 inches. If the weight still seems unusual, compare the density with the one your supplier gives.

## Sources

- Engineering ToolBox, Dirt and Mud - Densities (gravel, dry 105 lb/ft³). https://www.engineeringtoolbox.com/dirt-mud-densities-d_1727.html
- NIST Handbook 44 (2026), Appendix C, General Tables of Units of Measurement: 1 cubic yard = 27 cubic feet; 1 short ton = 2,000 pounds. https://www.nist.gov/document/2026-nist-handbook-44-appendix-c