How it works
The calculator works out the area of the shape you choose, multiplies it by the depth and adds any extra you enter. With a load size, it divides the volume by it and rounds up.
Rectangle: Area = Length × Width
Circle: Area = π × (Diameter ÷ 2)²
Triangle: Area = ½ × Base × Height
Volume = Area × Depth × (1 + Extra ÷ 100)
Cubic yards = Cubic feet ÷ 27
Loads = ⌈ Volume ÷ Load size ⌉
⌈ ⌉ means rounding up to the next whole load. Units are converted internally with the exact factors from NIST Handbook 44: 1 in = 2.54 cm, so 1 cubic yard = 27 cubic feet = 0.764555 m³. You can enter lengths in feet or meters and the depth in inches or centimeters in any combination.
Worked example
Inputs
- Shape
- Rectangle or square
- Length
- 10 ft
- Width
- 10 ft
- Depth
- 4 in
- Extra
- 0 %
Result
- Volume
- 1.23 cu yd (33.33 cu ft)
- Same volume in other units
- 0.944 m³
- Area
- 100 sq ft
Common mistakes
- Entering the depth in feet instead of inches. A 4 in layer is a third of a foot; typing “4 ft” gives twelve times the volume.
- Dividing cubic feet by 9 instead of 27. A cubic yard is 3 × 3 × 3 = 27 cubic feet; 9 is the number of square feet in a square yard.
- Using the radius as the diameter for a circle. The diameter is the full distance across; using the radius instead quarters the area.
- Taking a sloping side as the triangle’s height. The height is measured at a right angle to the base.
- Ordering the measured volume of a material that compacts. Loose stone, soil and mulch settle, so more goes in than the finished layer holds.
Assumptions and limits
- The area is a rectangle, a circle or a triangle, and the depth is the same everywhere. Split other shapes into these and add the volumes.
- Volume = area × depth, plus any extra you enter. No allowance for compaction or settling is assumed.
- The calculator gives volume only. For weight, multiply by your supplier’s density, or use the gravel, sand or topsoil calculator.
- Loads are rounded up to whole loads; the volume itself is not rounded.
Frequently asked questions
How do I calculate cubic yards?
Multiply length × width × depth in feet to get cubic feet, then divide by 27. A 10 × 10 ft area 4 in deep is 10 × 10 × 0.333 = 33.3 cubic feet, or 1.23 cubic yards.
How many cubic feet are in a cubic yard?
27 – a cubic yard is 3 ft × 3 ft × 3 ft (NIST Handbook 44). One cubic yard is also about 0.765 cubic meters.
How many square feet does a cubic yard cover?
It depends on the depth. One cubic yard covers 324 sq ft at 1 in, 162 sq ft at 2 in, 108 sq ft at 3 in and 81 sq ft at 4 in.
How do I find the volume of a round area?
The area of a circle is π × (diameter ÷ 2)². A circle 8 ft across is 3.1416 × 4 × 4 = 50.3 sq ft; at 6 in deep that is 25.1 cubic feet, or 0.93 cubic yards.
How many bags make a cubic yard?
Divide 27 by the bag size in cubic feet – for example 27 ÷ 2 = 13.5, so 14 bags of 2 cu ft. Check the volume printed on your bag; enter it as the bag size to get the count.
Sources
- NIST Handbook 44, Appendix C – General Tables of Units of Measurement — National Institute of Standards and Technology. Exact unit definitions: 1 in = 2.54 cm, 1 yd³ = 27 ft³, 1 US gal = 231 in³, 1 lb = 0.45359237 kg.
Method reviewed November 5, 2026