Gravel Calculator — cubic yards and tons

How it works

Gravel for a path, driveway or drainage bed is worked out by volume, then converted to weight if you are buying by the ton:

cubic yards = (length × width × depth) ÷ 27

with the dimensions in feet (depth is entered in inches and converted, ÷12). Dividing by 27 gives cubic yards because one cubic yard is 27 cubic feet.

To get the weight, multiply the cubic yards by the density:

tons = cubic yards × density

Gravel runs around 1.4 tons per cubic yard, but it varies with the stone type and moisture, so density is an input — set it to your supplier's figure. Order about 5–10% extra to allow for compaction and spreading.

Worked example

A 20 × 10 ft path at 3 inches deep is 20 × 10 × 0.25 = 50 cubic feet = 1.85 cubic yards. At 1.4 tons per cubic yard that is about 2.6 tons. A larger 40 × 10 ft driveway, 4 inches deep, comes to about 4.94 cubic yards (roughly 6.9 tons).

Frequently asked questions

How much gravel do I need?

Multiply length × width × depth (in feet) and divide by 27 for cubic yards. If the depth is in inches, divide it by 12 first. For weight, multiply the cubic yards by the density (about 1.4 tons per cubic yard for gravel).

How many tons of gravel are in a cubic yard?

Around 1.4 tons per cubic yard for typical gravel, though it ranges from about 1.2 to 1.7 depending on the stone size, type and moisture. This calculator uses the density you enter, so adjust it to your material for an accurate tonnage.

How deep should a gravel layer be?

Common depths are 2–3 inches for a decorative or walking path and 4 inches or more for a driveway, often over a compacted base. Deeper layers or vehicle traffic usually need a sub-base, which you would calculate as a separate layer.

How much extra gravel should I order?

Add roughly 5–10%. Gravel compacts as it is driven on and settles, and some is always lost spreading and leveling. It is cheaper to have a little left than to reorder a small top-up.

Should I order gravel by the yard or the ton?

Either — they describe the same material by volume or weight. Bulk suppliers often price by the ton, so convert your cubic yards to tons with the density. This calculator gives both so you can order in whichever unit your supplier uses.

What is the difference between gravel and mulch calculations?

The volume calculation is identical — area times depth. Gravel is sold by weight, so this page converts to tons via density; mulch is sold in bags, so the mulch calculator divides the volume by the bag size instead.