Square Feet to Cubic Yards Calculator
This square feet to cubic yards calculator needs one extra number, the depth, because area alone cannot be turned into volume. Enter both and read the yards to order.
You cannot convert square feet to cubic yards directly, because one is area and the other is volume. Add a depth: multiply square feet by depth in feet, then divide by 27. For 400 sq ft at 4 inches deep that is 133.3 cubic feet, or 4.94 cubic yards, and 5.43 yards with 10% extra.
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Result
How to convert square feet to cubic yards
Square feet measure area; cubic yards measure volume. There is no fixed conversion between them, because the result depends on how deep the material is. Once you pick a depth, the conversion is simple: convert the depth to feet, multiply by the area to get cubic feet, then divide by 27 (there are 27 cubic feet in a cubic yard).
cubic yards = cubic feet ÷ 27
Example: 400 sq ft at 4 inches deep is 400 × 0.3333 = 133.3 cubic feet, which is 4.94 cubic yards. Add 10% for waste and settling and you order 5.43 cubic yards, about 7.6 tons of gravel at 1.4 tons per yard.
Coverage of one cubic yard at common depths
| Depth | Square feet covered by 1 cubic yard |
|---|---|
| 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 |
| 8 in | 41 sq ft |
| 12 in | 27 sq ft |
The rule of thumb: 324 ÷ depth in inches gives the square feet that one cubic yard covers. At 3 inches, one yard covers 108 sq ft; at 2 inches, 162 sq ft.
Quantities for common areas at 4 inches deep
| Area | Cubic yards |
|---|---|
| 100 sq ft | 1.23 |
| 200 sq ft | 2.47 |
| 300 sq ft | 3.70 |
| 500 sq ft | 6.17 |
| 1000 sq ft | 12.35 |
Common mistakes
- Dividing square feet by 27 directly. That skips the depth and gives a wrong answer.
- Mixing inches and feet. Convert the depth to feet before multiplying, or divide by 12.
- Forgetting waste. Uneven ground, settling and compaction mean you usually need 5–15% more.
For other shapes use the cubic yard calculator; to convert yards to weight, use the yards to tons calculator; for a mulch bed see the mulch calculator.
Frequently asked questions
How do I convert square feet to cubic yards?
Multiply the square feet by the depth in feet (inches ÷ 12) to get cubic feet, then divide by 27.
How many square feet does a cubic yard cover?
Divide 324 by the depth in inches. At 3 inches one cubic yard covers 108 sq ft; at 4 inches, 81 sq ft.
Why can't I convert square feet to cubic yards without a depth?
Square feet measure a flat area and cubic yards measure a volume. The depth is the missing dimension.
How many cubic yards for 1,000 square feet?
At 4 inches deep, about 12.35 cubic yards. At 2 inches, about 6.17.
Should I add extra for waste?
Usually yes: 5–15% covers settling, uneven ground and spills.
Sources and further reading
- NIST Special Publication 811: conversion factors — National Institute of Standards and Technology
These references support the general guidance on this page. The calculator applies the standard formulas shown above to the numbers you enter.
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. Estimates only. Always confirm quantities with your supplier or a qualified contractor before ordering, and add extra for waste and site conditions.