Stone Calculator
Buying crushed stone, pea gravel or decorative rock? Use this free stone calculator to work out exactly how much stone you need for a driveway, path or garden bed. Enter the length, width and depth in inches to get cubic yards, tons and the number of bags, plus an estimated cost.
Need a different material? Try the Gravel Calculator, the Concrete Calculator or the main Cubic Yard Calculator.
Use this if you already know the square footage — for example from a listing, a plan, or a measuring app.
Most mulch and topsoil beds need 2–3 inches; gravel driveways 4–6 inches.
The material sets the weight and bag estimate — densities are typical averages.
Most rocks and soils fall between 2,200 and 3,000 lb per cubic yard.
Add your supplier’s price to see the estimated total cost.
Order tip: add 5–10% extra for waste, spillage and compaction — material settles once it is spread and rained on. The suggested order amount above already includes a 10% allowance, rounded up to the nearest half yard.
How to Calculate Stone in Cubic Yards
Measure the length and width of the area in feet and the stone depth in inches, then work it out in three steps:
- Turn the depth into feet: depth in inches ÷ 12. For example, 4 inches is 4 ÷ 12 = 0.33 feet.
- Find the volume in cubic feet: length × width × depth in feet.
- Convert to cubic yards: divide the cubic feet by 27, because one cubic yard holds 27 cubic feet.
Formula: Cubic yards = (length in feet × width in feet × depth in inches ÷ 12) ÷ 27.
Example: A driveway 20 feet long, 10 feet wide and 4 inches deep needs 2.47 cubic yards:
- Depth in feet: 4 ÷ 12 = 0.33 feet.
- Volume in cubic feet: 20 × 10 × 0.33 = 66.7 cubic feet.
- Cubic yards: 66.7 ÷ 27 = 2.47 cubic yards.
- Weight: 2.47 × 2,700 ≈ 6,670 pounds, or 3.3 tons.
- Bags: 66.7 ÷ 0.5 = 134 bags of 0.5 cu ft (50 lb).
Stone settles and compacts, so add about 10% extra for waste and compaction.
Crushed Stone vs Pea Gravel vs Decorative Rock
Stone is not one material — pick the type that suits the job:
| Type | Best for | Notes |
|---|---|---|
| Crushed stone (3/4 in) | Driveways, paths and drainage | Angular pieces lock together and compact well. |
| Pea gravel | Garden beds, play areas and paths | Rounded and smooth underfoot, but shifts more. |
| Decorative rock / river rock | Borders, landscape beds and ground cover | Sold in a range of sizes and colours. |
| Decomposed granite | Patios and paths | Its fines compact down to a firm, walkable surface. |
How Much Does a Cubic Yard of Stone Weigh?
A cubic yard of crushed stone weighs about 2,700 pounds, or 1.35 tons. Pea gravel is a little heavier, at about 2,800 pounds a yard, and decorative rock varies with the stone type.
Stone is heavy, so most half-ton pickup trucks carry about 1 cubic yard of stone per load — check your truck’s payload rating before you load.
Stone Depth Guide
- Driveways: 4–6 inches, over a compacted base.
- Paths and walkways: 2–3 inches.
- Garden beds: 2–3 inches.
- Drainage trenches: 6 inches.
Put landscape fabric underneath to keep weeds down and stop the stone sinking into the soil.
Frequently Asked Questions
How many tons of stone are in a cubic yard?
One cubic yard of crushed stone weighs about 1.35 tons. So 2 cubic yards weigh about 2.7 tons, and 10 cubic yards weigh about 13.5 tons.
How much stone do I need for a 10×10 area?
At 4 inches deep, a 10 ft × 10 ft area needs 1.23 cubic yards, or about 1.7 tons. At 3 inches it is 0.93 yards (1.3 tons), and at 6 inchess it is 1.85 yards (2.5 tons).
How many bags of stone are in a cubic yard?
A cubic yard holds 27 cubic feet, so it takes 54 bags of 0.5 cu ft (50 lb) stone to make a cubic yard. For a whole project, multiply the cubic yards you need by 54 and round up.
What size stone should I use for a driveway?
Three-quarter-inch (3/4 in) crushed stone is the usual choice for driveways — it locks together and compacts well. Pea gravel is better for garden beds and play areas, but it shifts more under car tyres.
More calculators: Gravel Calculator, Concrete Calculator and the main Cubic Yard Calculator.