Calculator + chartEnter your measurements below and it works the answer out.
A cubic yard is 27 cubic feet. Spread D inches deep it covers 324 ÷ D square feet — 324 at one inch, 162 at two, 108 at three, 81 at four. Enter your area and depth for the volume in both units.
| Depth | Square feet covered | Square feet per cubic foot |
|---|---|---|
| 1 in | 324 sq ft | 12 sq ft |
| 2 in | 162 sq ft | 6 sq ft |
| 3 in | 108 sq ft | 4 sq ft |
| 4 in | 81 sq ft | 3 sq ft |
| 5 in | 64.8 sq ft | 2.4 sq ft |
| 6 in | 54 sq ft | 2 sq ft |
| 8 in | 40.5 sq ft | 1.5 sq ft |
| 12 in | 27 sq ft | 1 sq ft |
Every figure here is 324 ÷ depth in inches, because a cubic yard is 27 cubic feet and one square foot at D inches deep is D/12 of a cubic foot. Nothing on this site uses a coverage number that does not come out of that line.
The definition. A yard is three feet, so a cubic yard is 3 × 3 × 3 = 27 cubic feet. That is not a convention or an industry figure — it is what the unit means, and everything else on this site is built on it.
The coverage line. One square foot at D inches deep is D/12 of a cubic foot. So one cubic yard spread D inches deep covers 27 ÷ (D/12) = 324 ÷ D square feet. At 3 inches that is 108 square feet; at 4 inches, 81. Every coverage figure on BuildCalcy comes out of this one line, which is why none of them can disagree with each other.
Working the other way. To go from an area to an order: area in square feet × depth in feet ÷ 27 = cubic yards. A 20 by 12 ft area at 3 inches is 240 × 0.25 ÷ 27 = 2.22 cubic yards.
Why suppliers use yards and not feet. A cubic yard is roughly what fits in a small dump trailer and is the unit trucks are loaded and priced by. Most yards have a one-cubic-yard minimum and a short-load fee below about three, so the number this gives you is the number to quote on the phone.
Waste. This page adds 10%, which is the general-purpose allowance. The individual material pages use the figure that suits each one — 5% for mulch, topsoil, asphalt and sod, 10% for concrete, gravel and sand.
27. A yard is three feet, and 3 × 3 × 3 is 27. It is the conversion that every bulk material order runs through.
It depends entirely on depth: 324 sq ft at 1 inch, 162 at 2 inches, 108 at 3, 81 at 4, 54 at 6, and 27 at 12 inches. The figure is always 324 divided by the depth in inches.
Multiply the square feet by the depth in feet, then divide by 27. For a depth given in inches, divide the inches by 12 first — 4 inches is 0.333 ft, not 0.4.
A half-ton pickup bed holds roughly two cubic yards of mulch by volume, but only about one cubic yard of gravel or soil before you are over the payload. Volume runs out after weight does with anything heavier than bark.
How far one cubic yard spreads. It falls out of the definition: 27 cubic feet ÷ (depth in inches ÷ 12) = 324 ÷ depth. Doubling the depth halves the coverage, which is the single most useful thing to know before ordering.