From area to cubic yards
Bulk landscape material is sold by the cubic yard (volume) or the ton (weight). Start with volume: length × width in feet times depth in feet. Depth is usually given in inches, so divide by 12 first. A cubic yard is 3 × 3 × 3 feet, or 27 cubic feet, so divide cubic feet by 27.
One cubic yard spread 3 inches deep covers 108 square feet, and spread 2 inches deep it covers 162 square feet. That is a handy check against a supplier's quote.
From cubic yards to tons: why density varies
To convert volume to weight you need the material's bulk density, and that is where every calculator is approximate. Penn State's civil engineering course notes give normal-weight aggregate a dry-rodded unit weight of 1,100 to 1,750 kg/m³ (about 0.93 to 1.47 tons per cubic yard), and crushed stone 1,450 to 1,750 kg/m³ (about 1.22 to 1.47 tons per cubic yard). Moisture adds weight on top of that.
Soils vary too. The University of Illinois soil quality guide lists healthy bulk densities below about 1.10 g/cm³ for clayey soils and below 1.60 g/cm³ for sandy soils (about 0.93 to 1.35 tons per cubic yard). Wood chips are far lighter: EPA volume-to-weight factors put them at 243 lb per cubic yard dry and 473 lb green, or about 0.12 to 0.24 tons.
The defaults here (1.4 for gravel and crushed stone, 1.35 for sand, 1.1 for topsoil and 0.18 for mulch) sit inside those ranges, but they are planning figures, not a property of the stone in your driveway. If you are buying by the ton, ask the supplier what a cubic yard of their material weighs and use the custom option.
Getting the depth right
Loose material settles and compacts, especially gravel driveways and base layers that are rolled or tamped. Order more than the finished depth implies; the default 10% extra is a starting point, and compacted base layers can need considerably more. Measure depth after any excavation, not from the top of the existing grass or soil.
The formulas
Cubic yards = L × W × (D ÷ 12) × (1 + extra ÷ 100) ÷ 27Tons = cubic yards × densityBags = round up (cubic feet ÷ bag size)- L, W = length and width in feet
- D = depth in inches
- density = tons per cubic yard for the material
Example: a 20 × 10 ft gravel path, 3 inches deep
- Volume: 20 × 10 × (3 ÷ 12) = 50 cubic feet.
- Add 10% extra: 50 × 1.10 = 55 cubic feet, or 55 ÷ 27 = 2.04 cubic yards (1.56 m³).
- Weight at 1.4 tons per cubic yard: 2.04 × 1.4 = 2.85 tons.
- In 0.5 cu ft bags: 55 ÷ 0.5 = 110 bags, which is why bulk delivery is usually easier for anything bigger than a small bed.
Frequently asked questions
How many tons of gravel are in a cubic yard?
It depends on the stone and how wet it is. This calculator uses 1.4 tons per cubic yard for gravel; published ranges for dry aggregate run from about 0.93 to 1.47 tons per cubic yard. Ask your supplier for their figure.
How much area does a cubic yard of gravel cover?
At 3 inches deep, 108 sq ft; at 2 inches, 162 sq ft; at 4 inches, 81 sq ft. Divide 324 by the depth in inches to get square feet per cubic yard.
How many bags of mulch make a cubic yard?
A cubic yard is 27 cubic feet, so it takes 13.5 bags of 2 cu ft (round up to 14) or 9 bags of 3 cu ft.
How much does a cubic yard of mulch weigh?
Much less than stone. EPA volume-to-weight factors list wood chips at 243 lb per cubic yard dry and 473 lb green. This calculator uses 0.18 tons (360 lb), roughly the midpoint.
Should I order by the ton or by the yard?
Order in whatever unit the supplier prices in, but plan in cubic yards, because volume is what fills your space. Convert with the supplier's density so the weight you order covers the volume you need.
Sources
Last reviewed for 2026. How we calculate.