Gravel Calculator

Gravel Types

Gravel comes in three main types: pea gravel, crushed stone, and river rock. Pea gravel is small and rounded, used for pathways and beds. Crushed stone is angular and locks together for driveways and drainage. River rock is smooth and decorative. Weight differs by type: pea gravel is about 1.25 to 1.35 tons per cubic yard, crushed stone is 1.42, and river rock is about 1.5. The calculator multiplies the volume by the chosen weight to get tons, since gravel is delivered and billed by the ton. A 20 x 10 ft area at 3 inches deep is 1.85 cubic yards, or about 2.6 tons of crushed stone.

Tons per Yard

Gravel is sold by the ton, so converting your volume to tons is the key step. A cubic yard of typical gravel weighs about 2,830 pounds, or 1.42 tons. The calculator finds cubic yards from length, width, and depth, then multiplies by the weight per yard. One ton of gravel covers about 100 square feet at 2 inches deep, 70 square feet at 3 inches, or 50 square feet at 4 inches. The table shows coverage and tonnage for common projects. Order 10 percent extra to account for spreading and settling.

Driveway Math

A gravel driveway is built in layers, not one deep pour. The recommended total depth is 6 to 9 inches, laid as three layers. The base is 4 inches of large #3 crushed stone, 1 to 2 inches in size. The middle is 3 inches of #57 stone, about three-quarters of an inch. The top is 2 inches of #8 stone or pea gravel for a smooth finish. Calculate each layer separately by depth, then add the tonnage. A 30 x 12 ft driveway at 6 inches total needs about 6.7 cubic yards, or 9.5 tons of crushed stone, plus 10 percent for compaction.

What gravel is best for a driveway?

Crushed stone is the best gravel for a driveway because its angular edges lock together into a firm, stable surface. Pea gravel is too round and shifts under tires. Use the layered approach with a #3 crushed base, a #57 middle, and a #8 or pea gravel top for the cleanest finish. The angular base layer carries the weight, while the finer top layer fills the gaps and smooths the drive.

How much does a ton of gravel cover?

One ton of gravel covers about 100 square feet at 2 inches deep, 70 square feet at 3 inches, and 50 square feet at 4 inches. Coverage drops as depth rises because the same weight spreads thinner over more area or thicker over less. For a quick estimate, a single ton handles a small bed or a short path section at standard depth. Larger driveways need several tons across the layered build.

Gravel Sizes Explained

Gravel is sorted by number, and the number tells you the stone size. Number 3 stone is 1 to 2 inches, used as a driveway base layer. Number 57 stone is about three-quarters of an inch, the most common all-purpose size for drainage and middle layers. Number 8 stone is three-eighths of an inch, used as a smooth top layer. Pea gravel is small and rounded for paths and decorative beds. Crusher run is a mix of stone and fines that compacts into a hard base.

Match the size to the job. A driveway uses large base stone for strength, a middle layer for stability, and a fine top layer for a smooth finish. Drainage trenches use number 57 stone because water flows freely between the angular pieces. Decorative beds use pea gravel or river rock for looks. Order the right size the first time, since mixing sizes after the fact rarely produces a clean result. Add 10 percent extra for spreading and compaction.

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