Crushed Stone Calculator
Work out how much crushed stone you need in tons, cubic yards and bags. It starts with a 20 × 10 ft base, 4 inches deep, with a 15% allowance for compaction.
1. Measure your area
2. Choose your gravel
Gravel density varies by material, moisture and supplier. Use your supplier's stated density when available. This calculator provides an estimate, not a supplier quote.
What is crushed stone?
Crushed stone is rock that has been broken into angular pieces and screened to a size. Because the edges are sharp, the pieces lock together when spread and compacted, which makes a firm surface. That is why it is the usual choice for driveway bases, paver bases, drainage and anywhere that needs a stable, free-draining layer. Round stones such as pea gravel do not lock together in the same way.
Common types
Names and grades differ by region and quarry, so ask your supplier what they stock. Two you will see often:
- Clean stone, such as #57. Washed or screened stone of roughly 1/2 to 1 inch with little dust. It drains freely and is used for drainage, pipe bedding and driveway bases.
- Crusher run (also called dense-graded aggregate). A mix of stone and fine particles that compacts very firmly. It is popular as a base under patios, walkways and slabs. Because the fines fill the gaps, it can weigh more per cubic foot than clean stone, so choose Custom density in the calculator if your supplier gives a figure.
How deep should a crushed stone base be?
For a patio or walkway base, about 4 to 6 inches of compacted stone is common. Driveways and areas that carry vehicles usually need more, and soft or wet ground or a freezing climate may call for extra depth. For best results, spread and compact the stone in layers of a few inches at a time rather than all at once. Your supplier or contractor can tell you what suits your soil.
Worked example: a 20 × 10 ft base at 4 inches
Area: 20 ft × 10 ft = 200 sq ft
Volume at 4 inches deep: 200 × (4 ÷ 12) = 66.67 cubic feet
Add 15% for compaction and waste: 66.67 × 1.15 = 76.67 cubic feet = 2.84 cubic yards
Weight at 110 lb per cubic foot: 76.67 × 110 = 8,433 lb = 4.22 tons
How much area does crushed stone cover?
These figures use 110 lb per cubic foot and no allowance for compaction. Add 10 to 15% on top for real jobs.
| Depth | Sq ft per ton | Sq ft per cubic yard |
|---|---|---|
| 2 inches | 109 | 162 |
| 4 inches | 55 | 81 |
| 6 inches | 36 | 54 |
Setting up a base under a patio? See the gravel patio calculator. For vehicles, use the driveway gravel calculator.
Frequently asked questions
How many tons of crushed stone do I need?
Multiply the area by the depth to get the volume, add 10 to 15% for compaction, then multiply by the stone's weight per cubic foot. A 20 × 10 ft area at 4 inches deep with a 15% allowance needs about 4.2 tons. The calculator above does this for any size.
How much does a cubic yard of crushed stone weigh?
Roughly 1.4 to 1.5 tons for clean crushed stone, or about 2,800 to 3,000 lb. Dense-graded mixes such as crusher run can be heavier. Ask your supplier for their figure if you need an exact weight.
What size crushed stone should I use?
It depends on the job. Larger clean stone suits drainage and the lower layers of a thick base, while a mix with fines such as crusher run suits a base that must compact firmly. Ask a local supplier to recommend a grade for your project.
Is crushed stone the same as gravel?
People use the words loosely. Strictly, gravel is naturally rounded stone and crushed stone is broken rock with angular edges. This site treats both as loose aggregate sold by the ton or cubic yard, and the calculation is the same.
How much extra crushed stone should I order?
Add 10 to 15% for a base that will be compacted. If you are only topping up an existing firm surface, 5 to 10% is usually enough.
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Last updated 2026-10-06. Quantities are estimates; densities and coverage vary by material, moisture and supplier.