How Much Gravel Do I Need? The Formula for Any Project (With Cost)
Ordering the wrong amount of gravel is expensive in both directions. Too little means a second delivery fee. Too much means a pile of rock aging in your yard. Here is the math to get it right.
Every gravel project starts with the same calculation: length × width × depth. A 20-foot driveway that is 10 feet wide with 4 inches of gravel needs: 20 × 10 × 0.33 feet = 66 cubic feet = 2.44 cubic yards. At roughly 1.4 tons per cubic yard for crushed stone, that is about 3.4 tons. At $30-50 per ton delivered, you are looking at $102-170 for the material.
Where people go wrong: forgetting to convert inches to feet (4 inches = 0.33 feet, not 4 feet — that mistake has ordered $10,000 of gravel for a $200 project), not accounting for compaction (gravel settles 10-15% after being driven on, so add 10-15% to your calculated amount), and not considering the base layer (most driveways need 4-6 inches of coarse base rock below 2-3 inches of surface gravel).
Material Types and When to Use Each
Crushed stone (#57): The workhorse. Angular edges lock together for stability. Best for driveways, parking areas, and base layers. $30-40 per ton. Pea gravel: Smooth, round stones. Comfortable to walk on but shifts under tires. Best for walkways, garden paths, and decorative areas. Not recommended for driveways. $35-50 per ton. Decomposed granite (DG): Fine, sandy texture that packs hard when compacted. Excellent for patios and walkways. Needs edging to prevent spreading. $40-60 per ton.
For a standard residential driveway, the recommended layering from bottom to top: 4-6 inches of #3 or #4 crushed stone as the base, 2-3 inches of #57 crushed stone as the surface, and optionally 1 inch of stone dust on top for a smoother finish. Each layer should be compacted before the next is applied. Skipping the base layer saves money initially but leads to rutting, sinking, and a driveway that needs rebuilding within 3-5 years.
Calculate the exact amount you need for any project with our gravel calculator — enter your dimensions and it tells you cubic yards, tons, and approximate cost for 7 different material types.