How to Estimate the Gravel Needed for a Driveway

Measure the length and width of the driveway. For short driveways, you can use a measuring tape. For longer distances, you'll probably want to rent a measuring wheel from a building supply store. Multiply the length by the width to find the square footage of your driveway .

Determine how deep the gravel needs to be. For new driveways, you should dig out the bed before buying the gravel in order to make an accurate estimate. In general, you'll probably need a 10-inch to 12-inch thickness for a new driveway. For renovating an existing drive, about two inches is usually sufficient. Express this as a decimal fraction of a foot. For example, two inches is 0.17 feet.

Multiply the square footage by the desired thickness. For example, if the square footage is 1500 and you want a layer of 0.17 feet, multiply 0.17 times 1500 for a total of 250 cubic feet. Convert this to cubic yards by dividing by 27 (250/27 = 9.25 cubic yards).

Estimate the gravel for a driveway by weight. Gravel is usually sold by the ton. One cubic yard contains about 2750 pounds of gravel, or 1 3/8 tons. So multiply the amount from Step 3 (9.25 cubic yards) by 1 3/8 for a total of 12.7 tons. Add about 10 percent to ensure you have enough and to deal with unexpected situations. For this example, that means you need about 14 tons of gravel.