How do you convert square feet to cubic yards?
÷ 27after × depth
sq ft × depth in feet ÷ 27
Square feet alone cannot become cubic yards — you need a depth. Multiply the square footage by the depth in feet, then divide by 27. A 100 sq ft patio at 4 inches deep is 100 × 0.333 = 33.3 cubic feet, which is 1.23 cubic yards.
cubic yards = square feet × depth in feet ÷ 27
- Depth in inches ÷ 12 gives depth in feet: 2 in = 0.167, 3 in = 0.25, 4 in = 0.333, 6 in = 0.5
- One cubic yard covers 324 sq ft at 1 inch deep
- One cubic yard covers 108 sq ft at 3 inches deep
- One cubic yard covers 81 sq ft at 4 inches deep
- 100 sq ft at 4 inches deep is 1.23 cubic yards
One cubic yard covers this much area
| Depth | Area covered by 1 yd³ |
|---|---|
| 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 |
| 12 in | 27 sq ft |
Cubic yard calculator
Any area and depth — in cubic yards, feet, metres and tons.
Turning inches into feet
Depths are quoted in inches and volumes in feet, which is where most mistakes happen. Divide inches by 12 first: 2 in = 0.167 ft, 3 in = 0.25 ft, 4 in = 0.333 ft, 6 in = 0.5 ft.
Worked example
A 20 × 30 ft driveway at 4 inches: 600 sq ft × 0.333 ft = 200 cubic feet. 200 ÷ 27 = 7.4 cubic yards. Add the usual 10% for an uneven subgrade and you order 8.15 cubic yards.
Frequently asked questions
How many square feet are in a cubic yard?
It depends on the depth. One cubic yard covers 324 sq ft at 1 inch, 108 sq ft at 3 inches, 81 sq ft at 4 inches and 27 sq ft at 12 inches.
How do I convert square feet to cubic yards?
Multiply square feet by the depth in feet, then divide by 27.
How many cubic yards is a 10 × 10 ft area at 4 inches?
100 sq ft × 0.333 ft = 33.3 cubic feet, which is 1.23 cubic yards.