How to use the stone calculator
- Select your material type from the dropdown, such as crushed stone, pea gravel or river rock.
- Enter the length and width of the area in feet.
- Enter the desired depth in inches (typically 2 to 4 inches for most stone applications).
- Optionally enter the price per ton to see an estimated total cost.
- Read the results for volume in cubic yards, weight in US tons and estimated cost.
How the stone calculator works
The calculation converts your dimensions into cubic yards, then multiplies by the material density to get weight. First, convert depth from inches to feet by dividing by 12. Then multiply length, width and depth in feet to get cubic feet. Divide by 27 to convert to cubic yards. Finally, multiply cubic yards by the density in pounds per cubic yard and divide by 2,000 to get US tons.
For example, a 10 ft by 10 ft area at 3 inches deep using crushed limestone (2,700 lb/yd³): depth is 3 / 12 = 0.25 ft. Volume is 10 x 10 x 0.25 = 25 ft³. In cubic yards that is 25 / 27 = 0.926 yd³. Weight is 0.926 x 2,700 = 2,500 lb, which equals 1.25 tons.
Common stone densities
Different types of stone have different bulk densities because of their mineral composition and how tightly the pieces pack together. The values below are typical averages used by this rock calculator. Actual density varies by quarry and moisture content.
| Material | Density (lb/yd³) |
|---|---|
| Crushed limestone | 2,700 |
| Crushed granite | 2,800 |
| Pea gravel | 2,700 |
| River rock (small, 1-3") | 2,600 |
| River rock (large, 3-6") | 2,900 |
| Decomposed granite | 2,500 |
| Lava rock | 1,200 |
| Marble chips | 2,700 |
If your supplier provides a specific density, select "Custom density" and enter it directly.
Choosing the right stone for your project
Each aggregate serves a different purpose. Crushed limestone and crushed granite are angular, so they lock together under compaction. That makes them ideal for driveway bases, patio sub-bases and road foundations. If you need a structural base, pair this tool with the concrete calculator to plan any concrete pours on top.
Pea gravel has smooth, rounded stones about 3/8 inch across. It is comfortable underfoot and drains well, making it popular for walkways, playgrounds and garden borders. River rock comes in larger sizes and is primarily decorative, used in dry creek beds, landscape accents and drainage swales.
Decomposed granite is finely crushed rock that compacts into a firm, natural-looking surface. It is widely used for paths, patios and xeriscaping. Lava rock is extremely lightweight and porous, best suited for decorative mulch replacement where soil insulation matters more than structural support.
Recommended depths for stone layers
Getting the depth right prevents the stone from shifting or exposing the ground beneath. Use these guidelines when entering values into the crushed stone calculator:
- Walkways and garden paths: 2 to 3 inches of pea gravel or decomposed granite over a compacted base.
- Driveways: 4 to 6 inches of crushed stone, often applied in two layers of different sizes.
- Drainage beds and French drains: 6 to 12 inches of river rock or washed gravel surrounding a perforated pipe.
- Decorative landscape beds: 2 to 3 inches of river rock or marble chips over landscape fabric.
Always account for compaction. Angular crushed rock settles roughly 10 to 15 percent after tamping, so you may want to order slightly more than the raw calculation shows.
Ordering tips and common mistakes
Stone is sold by the ton at most quarries and landscape suppliers, but sometimes by the cubic yard. This crushed rock calculator gives you both units so you can match whatever your supplier uses. One common mistake is confusing US short tons (2,000 lb) with metric tonnes (2,204.6 lb). This tool uses US short tons.
Another issue is forgetting to measure the area accurately. Use a tape measure or measuring wheel rather than pacing off distances. For irregular shapes, break the area into rectangles, calculate each separately and add the weights together. You can use the square footage calculator to help determine the area of complex shapes before entering the numbers here.
Finally, always add 5 to 10 percent extra to your final order to cover spillage, uneven ground and settling. If you are working with lava rock, remember its density is less than half that of granite, so a given volume weighs far less.
Worked examples
| Example | Input | Result |
|---|---|---|
| Driveway with crushed limestone | Material type: crushed-limestone; Length (feet): 40; Width (feet): 12; Depth (inches): 4; Price per ton ($): 55 | Volume: 5.93 yd³; Volume: 160.00 ft³; Weight: 8.00 tons; Weight: 16,000 lb; Estimated cost: $440.00 |
| Garden path with pea gravel | Material type: pea-gravel; Length (feet): 30; Width (feet): 3; Depth (inches): 2 | Volume: 0.56 yd³; Volume: 15.00 ft³; Weight: 0.75 tons; Weight: 1,500 lb |
| Decorative river rock bed | Material type: river-rock-small; Length (feet): 15; Width (feet): 8; Depth (inches): 3; Price per ton ($): 85 | Volume: 1.11 yd³; Volume: 30.00 ft³; Weight: 1.44 tons; Weight: 2,889 lb; Estimated cost: $122.78 |
| Patio base with decomposed granite | Material type: decomposed-granite; Length (feet): 12; Width (feet): 12; Depth (inches): 4; Price per ton ($): 60 | Volume: 1.78 yd³; Volume: 48.00 ft³; Weight: 2.22 tons; Weight: 4,444 lb; Estimated cost: $133.33 |
FAQ
How do I calculate how much stone I need?
Multiply the length by the width by the depth (all converted to feet) to get cubic feet. Divide by 27 to get cubic yards, then multiply by the stone density in pounds per cubic yard and divide by 2,000 to get tons.
What is the difference between crushed stone and river rock?
Crushed stone has angular edges that interlock when compacted, making it suitable for structural bases. River rock is naturally rounded by water, so it shifts more easily and is better for decorative or drainage applications.
How much does a cubic yard of stone weigh?
Most dense stone like crushed limestone or granite weighs between 2,500 and 2,900 pounds per cubic yard, or about 1.25 to 1.45 tons. Lightweight materials like lava rock weigh around 1,200 pounds per cubic yard.
Should I buy stone by the ton or by the yard?
It depends on your supplier. Quarries typically sell by the ton, while some landscape yards sell by the cubic yard. This pea gravel calculator outputs both measurements so you can order using whichever unit your supplier requires.
How deep should I lay decomposed granite for a patio?
A typical decomposed granite patio needs 3 to 4 inches of material over a compacted sub-base. For heavy foot traffic, lean toward 4 inches and compact it in layers.
Does this calculator work for gravel too?
Yes. Pea gravel, crushed rock and river rock are all covered by the presets. For general-purpose gravel without a specific stone type, you may also want to try the dedicated gravel calculator.
Why is my actual stone usage higher than the estimate?
Stone settles and compacts after installation, especially angular crushed varieties. Uneven ground, spillage during delivery and edging gaps also consume extra material. Adding 5 to 10 percent to your calculated amount helps avoid running short.