The short answer: 27
One cubic yard is a cube that measures 3 feet long, 3 feet wide and 3 feet high. Multiply those together and you get 3 × 3 × 3 = 27 cubic feet. That's the whole reason the number is 27 and not 9 or 3: a yard is 3 feet in each of the three directions.
It's easy to mix this up with area. A square yard is 3 × 3 = 9 square feet. A cubic yard adds depth, so it's 27 cubic feet.
Converting both ways
- Cubic feet to cubic yards: divide by 27. For example, 54 cubic feet ÷ 27 = 2 cubic yards.
- Cubic yards to cubic feet: multiply by 27. For example, 1.5 cubic yards × 27 = 40.5 cubic feet.
- Cubic yards to cubic meters: multiply by 0.7646. One cubic yard is a little over three-quarters of a cubic meter.
- Cubic meters to cubic yards: multiply by 1.308.
Quick conversion chart
| Cubic yards | Cubic feet | Cubic meters |
|---|---|---|
| 0.25 | 6.75 | 0.19 |
| 0.5 | 13.5 | 0.38 |
| 1 | 27 | 0.76 |
| 2 | 54 | 1.53 |
| 3 | 81 | 2.29 |
| 5 | 135 | 3.82 |
| 10 | 270 | 7.65 |
From area and depth to cubic yards
Most projects start with an area in square feet and a depth in inches. To get cubic yards:
- Convert the depth to feet by dividing the inches by 12.
- Multiply length × width × depth (all in feet) to get cubic feet.
- Divide by 27 to get cubic yards.
Example: a 10 × 10 ft patio slab 4 inches thick is 10 × 10 × (4 ÷ 12) = 33.3 cubic feet, which is 33.3 ÷ 27 = 1.23 cubic yards.
A handy shortcut: one cubic yard covers 324 square feet at 1 inch deep. Divide 324 by your depth in inches to see how far a yard goes:
| Depth | Area one cubic yard covers |
|---|---|
| 1 in | 324 sq ft |
| 2 in | 162 sq ft |
| 3 in | 108 sq ft |
| 4 in | 81 sq ft |
| 6 in | 54 sq ft |
The cubic yard calculator does all three steps for rectangles and circles at once.
Cubic yards and bagged material
Garden centers sell mulch, soil and stone in bags labeled in cubic feet, so the number 27 is what links bags to bulk:
| Bag size | Bags per cubic yard |
|---|---|
| 0.5 cu ft | 54 |
| 0.75 cu ft | 36 |
| 1 cu ft | 27 |
| 1.5 cu ft | 18 |
| 2 cu ft | 13.5 |
| 3 cu ft | 9 |
Once a job needs more than two or three cubic yards, bulk delivery is usually cheaper than bags, even after the delivery fee.
Volume isn't weight
Stone and soil suppliers often price by the ton, not the yard, and a cubic yard of different materials weighs very different amounts. A yard of dry mulch can weigh a few hundred pounds, while a yard of crushed stone often weighs around 1.3–1.5 tons. Moisture adds weight too. When you order by the ton, ask the supplier for their conversion, or use the density settings in the gravel calculator.
Tips for ordering
- Add about 5–10% for settling, compaction and uneven ground.
- Measure depth in several places, not just at the edge.
- Round up to the supplier's minimum unit. Many sell in half- or quarter-yard steps.
- For loose material like mulch, remember it settles after the first rain.