How many cubic yards do I need?
Multiply length, width, and depth to get cubic feet, then divide by 27 because one cubic yard contains exactly 27 cubic feet.
20 ft × 10 ft at 6 in
100 ft³ before extra material
The calculation
Keep all dimensions in feet before multiplying. Apply the extra-material allowance after calculating the exact geometric volume.
Depth conversion table
| Depth | Depth in feet | Square feet covered by 1 yd³ |
|---|---|---|
| 2 in | 0.1667 ft | 162 ft² |
| 3 in | 0.25 ft | 108 ft² |
| 4 in | 0.3333 ft | 81 ft² |
| 6 in | 0.5 ft | 54 ft² |
| 12 in | 1 ft | 27 ft² |
Volume is not weight
Cubic yards measure space. Suppliers may sell gravel, sand, or aggregate by the ton, and the conversion depends on density, gradation, moisture, and compaction. Use the supplier’s tons-per-yard value or a material-specific calculator rather than applying one universal factor.
Before placing an order
- Measure several points when depth or grade varies.
- Subtract large areas that will not receive material.
- Confirm whether the supplier quotes loose or compacted volume.
- Ask about minimum order, delivery increment, and truck access.
- Choose an explicit extra allowance based on measurement uncertainty and settling.
Frequently asked questions
Why are there 27 cubic feet in a cubic yard?
A yard is three feet, so a cube one yard on each side is 3 × 3 × 3, or 27 cubic feet.
Should I round to the next whole yard?
Use the supplier’s selling increment. Some deliver fractional yards, while others have whole-yard or minimum-load rules.
Does compaction change the answer?
Yes. Loose material can occupy more volume than the finished compacted layer. Ask the supplier or installer for the suitable compaction allowance.