Free Gravel Calculator – Cubic Yards, Tons & Cost

Gravel Calculator Guide

The Gravel Calculator estimates cubic yards, tons, bags, and truck loads of crushed stone, pea gravel, or river rock for driveways, paths, drainage, and decorative beds. Measure the area to be covered in length and width (feet or meters) and decide on a finished depth based on use. Decorative ground cover needs only 2-3 inches; garden paths and walkways want 3-4 inches; a residential driveway typically needs 4-6 inches over a compacted base, and a base course under pavers or a shed often runs 6-8 inches. For irregular shapes, break the area into rectangles and circles, calculate each, and add them. The tool converts volume to weight using a typical gravel density of roughly 1.4 to 1.5 tons per cubic yard, though pea gravel runs lighter and dense crushed stone heavier, so treat tonnage as an estimate when ordering by weight from a quarry scale.

Formula: cubic yards = length(ft) x width(ft) x depth(in) / 12 / 27. The /12 converts inches of depth to feet; the /27 converts cubic feet to cubic yards (27 cu ft per yard). Worked example: a driveway 40 ft long x 12 ft wide at 5 inches deep = 40 x 12 x 5 / 12 / 27 = 2400 / 324 = 7.41 cubic yards. At about 1.45 tons per cubic yard that is roughly 10.7 tons. Metric check: 12.2 m x 3.7 m x 0.127 m = 5.73 cubic meters, which equals 7.5 cubic yards, confirming the figure. If buying in 0.5 cu ft bags, 7.41 cu yd x 27 = 200 cu ft / 0.5 = 400 bags, which is why bulk delivery wins on any sizable job. One standard dump truck carries roughly 10-14 cubic yards.

Add 10% to your volume for compaction and uneven subgrade; compactable crushed stone can lose 15-20% of its loose volume once rolled, so a base course should be ordered against the compacted, not loose, depth. The most frequent mistake is mixing units, entering depth in inches but treating it as feet, which inflates the order twelvefold; always confirm the depth field is inches. A second mistake is skipping the geotextile separation fabric over soft soil, which lets stone migrate into the subgrade and forces re-topping within a year. For driveways, a graded aggregate base meeting a gradation such as ASTM D2940 or local department-of-transportation specs compacts far better than rounded river rock, which never locks together and is best reserved for drainage. For pipe bedding and French drains, follow the trench detail in the relevant plumbing or drainage code and keep washed, angular stone around perforated pipe.