What this calculator does
Bulk landscaping and fill materials, including mulch, topsoil, compost, gravel and sand, are commonly sold by the cubic yard. This calculator turns the size of a bed, path or excavation into the volume to order.
Formula
Cubic yards = (L × W × D in feet) ÷ 27, then multiplied by (1 + allowance% ÷ 100).
L, W and D are length, width and depth. Depth is usually measured in inches, so divide by 12 to get feet (the unit selector does this for you).
Worked examples
Mulch bed: 20 ft × 10 ft, 3 in deep
- Depth = 3 ÷ 12 = 0.25 ft.
- 20 × 10 × 0.25 = 50 ft³.
- 50 ÷ 27 ≈ 1.852 yd³.
Gravel pad: 5 m × 3 m, 10 cm deep
- 5 × 3 × 0.10 = 1.5 m³.
- 1.5 ÷ 0.764555 ≈ 1.962 yd³.
Interpreting the result
The result is loose volume for the shape you measured. Some materials compact or settle after spreading, so an allowance may be sensible; your supplier can advise how much for their product. Suppliers often deliver in fixed increments, so round up to what they sell.
Common mistakes
- Forgetting to convert inches of depth to feet (3 in is 0.25 ft, not 3 ft).
- Dividing by 9 (square feet per square yard) instead of 27 (cubic feet per cubic yard).
- Estimating weight from volume without the supplier's density figure.
Assumptions and limitations
The area is treated as a rectangle with uniform depth. For irregular beds, split them into rectangles and add the results, or find the area with the area calculator and multiply by depth. No material weights or bag counts are assumed.
Related: concrete calculator, rectangular prism volume calculator, square footage calculator.
Frequently asked questions
How do I convert cubic feet to cubic yards?
Divide by 27. A cubic yard is a cube 3 ft on each side, so it contains 3 × 3 × 3 = 27 cubic feet.
How much area does a cubic yard cover?
It depends on depth. One cubic yard (27 ft³) spread 3 inches (0.25 ft) deep covers 27 ÷ 0.25 = 108 sq ft; at 2 inches deep it covers 162 sq ft.
How many tons is a cubic yard of gravel?
Weight depends on the material, moisture and how it is graded, so this calculator does not convert to tons. Ask your supplier for the weight per cubic yard of the specific product.