Formula
The yard is the volume in cubic feet divided by 27. Waste, if you set it, is applied before the weight preview. A known area is square feet times depth in feet. Metric mode treats the area as square metres and converts with 0.3048².
rectangle = L × W × D
circle = π r² D
triangle = ½ base × height × D
area = ft² × D
cubic yards = ft³ ÷ 27
This is the geometry the gravel, concrete, asphalt, and soil calculators start from. Steps, bag counts, and a settle allowance live on those pages.
Worked examples
10 × 10 ft × 4 in. 100 × 4/12 = 33.33 ft³ = 1.23 yd³.
A 4 ft diameter, 6 in deep. π × 2² × 0.5 = 6.28 ft³ = 0.23 yd³.
A triangle 6 ft base, 8 ft height, 3 in deep. ½ × 6 × 8 × 0.25 = 6 ft³ = 0.22 yd³.
Reference
Depth in inches, and the yards in a rectangular pad with no waste.
| Pad | 4 in | 6 in |
|---|---|---|
| 10 × 10 ft | 1.23 yd³ | 1.85 yd³ |
| 10 × 20 ft | 2.47 yd³ | 3.70 yd³ |
| 20 × 20 ft | 4.94 yd³ | 7.41 yd³ |
Questions
How many cubic feet are in a cubic yard?
27. A 10 by 10 foot slab at 4 inches is 33.33 cubic feet, which is 1.23 cubic yards.
How do I measure a circle or a triangle?
A circle uses the diameter: π × (diameter ÷ 2)² × depth. A triangle uses ½ × base × height × depth. If you already know the area in square feet, use Known area and enter that area times the depth.
Does this page order the material?
It gives the volume, and a weight only if you pick a preview density. Gravel, concrete, asphalt, and soil each have their own calculator with bag counts and the density that page stands behind.
Sources
- 1 cubic yard = 27 cubic feet. Circle and triangle are the ordinary area formulas times depth.