Gravel Calculator
Size up a gravel driveway, path, or base layer — enter the area and depth to get cubic yards to order and a rough weight in tons.
How it works
We start with volume. Length times width gives the area, and multiplying by the depth gives cubic feet — but depth is in inches, so we divide it by 12 first. A 20-by-12 pad at 3 inches deep works out to 60 cubic feet.
Gravel is sold by the cubic yard, and a yard is 27 cubic feet, so we divide by 27. That 60 cubic feet becomes about 2.22 cubic yards, which is the number a landscape-supply yard will want to hear.
Some suppliers price by weight instead. Gravel runs roughly 1.4 tons per cubic yard, so we multiply the yards by that to give you a ballpark tonnage. Actual weight shifts with stone type and moisture, so treat it as an estimate.
Frequently asked questions
How deep should gravel be?
Two to three inches suits a decorative top layer or a garden path. A driveway usually wants more depth built up in layers — often four inches or more of base plus a top course — so it holds up under vehicle weight.
Why does the tonnage change with stone type?
The 1.4 tons-per-yard figure is a general average. Dense crushed rock weighs more per yard than light lava rock or dry pea gravel, and wet gravel is heavier than dry. Ask your supplier for the density of the exact product.
Should I order extra gravel?
A little, yes. Gravel compacts as it settles and spreads unevenly over an imperfect subgrade, so rounding your order up by 5 to 10 percent keeps you from coming up short on the last stretch.