Gravel Calculator
Whether you are filling a driveway, laying a garden path, or backfilling a drainage trench, knowing how much gravel or crushed stone to order prevents costly under-delivery and unnecessary returns. This gravel calculator converts area dimensions and depth into cubic yards and cubic feet, then estimates weight in tons using a typical density of 1.5 tons per cubic yard. This density is a reasonable average for dry pea gravel, crushed limestone, and common driveway gravel, but it will vary by material type and moisture content. Wet or dense aggregates such as crushed basalt or wet limestone can reach 1.7 to 1.8 tons per cubic yard. Always confirm with your supplier. For irregularly shaped areas, break the space into rectangles and add the results from multiple calculations. You can also enter a bag size (such as 50 lb) to find out how many bags you would need instead of ordering bulk delivery. Add 10 to 15% to your calculated volume when ordering to account for settling, slight grade variation, and material lost during spreading. Gravel compacts roughly 20 to 30% when driven over repeatedly, so driveways may need periodic top-dressing to maintain the intended depth.
Gravel calculation formula
Cubic feet = Length (ft) x Width (ft) x Depth (ft)
Cubic yards = Cubic feet / 27
Tons = Cubic yards x 1.5 (approx density)
Bags = ceil(Tons x 2000 / Bag weight in lb)
Worked example: 20 x 10 ft driveway apron at 4 inches deep
- Depth in feet: 4 / 12 = 0.333 ft
- Cubic feet: 20 x 10 x 0.333 = 66.67 cu ft
- Cubic yards: 66.67 / 27 = 2.47 cu yd
- Tons: 2.47 x 1.5 = 3.70 tons
- 50 lb bags: ceil(3.70 x 2000 / 50) = 148 bags
Gravel calculator: frequently asked questions
How many cubic yards of gravel do I need?
Multiply the length (ft) by the width (ft) by the depth (ft), then divide by 27. For example, a 20 ft x 10 ft area at 4 inches deep = 20 x 10 x (4/12) / 27 = 2.47 cubic yards. This calculator does the conversion automatically when you enter depth in inches.
How much does a cubic yard of gravel weigh?
Gravel and crushed stone weight varies by type and moisture content. Dry pea gravel is about 1.35 tons per cubic yard. Wet crushed limestone can be 1.6 to 1.7 tons per cubic yard. This calculator uses 1.5 tons per cubic yard as a typical average for common landscaping and driveway gravel. Always confirm the specific density with your supplier.
How deep should I lay gravel for a driveway?
A gravel driveway typically needs 4 to 6 inches of compacted gravel. A three-layer approach works best: 4 to 6 inches of large base stone (2 to 3 inch), topped with 2 to 3 inches of medium stone (1.5 inch), then 2 to 3 inches of fine gravel or pea gravel on top. For a simple single-layer driveway, 4 inches of 1.5-inch crushed stone is a common minimum.
How deep should garden path gravel be?
For decorative garden paths, 2 to 3 inches of pea gravel or decorative stone is typically sufficient. Install a weed barrier fabric underneath before laying the gravel. For areas subject to foot traffic, 3 to 4 inches provides better stability. Top up annually as gravel settles and displaces.
How many tons of gravel in a truckload?
A standard tri-axle dump truck carries 14 to 16 tons of gravel per load. A smaller single-axle truck carries about 7 to 8 tons. Bulk gravel is typically sold and delivered in full or half-truck increments. For small quantities (under 2 cubic yards), buying bagged landscape stone from a home improvement store may be more economical than arranging a bulk delivery.
Sources
- US Geological Survey Mineral Resources Program (aggregate data): usgs.gov.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology. Density varies by material; confirm with supplier.