Gravel guide
How Much Gravel Do I Need?
The amount of gravel you need depends on the length, width, and depth of your project. Gravel is usually measured in cubic yards or tons, depending on how your supplier sells it.
Multiply length by width by depth to find the volume. If using inches for depth, convert the depth to feet first. Then divide cubic feet by 27 to get cubic yards.
Use the Gravel Calculator →Gravel Formula
Depth must be in feet before using this formula. For example, 4 inches is 0.333 feet.
Common Gravel Estimates
| Area Size | Depth | Gravel Needed |
|---|---|---|
| 10 × 10 ft | 4 in | 1.23 yd³ |
| 20 × 20 ft | 4 in | 4.94 yd³ |
| 30 × 12 ft | 4 in | 4.44 yd³ |
| 40 × 20 ft | 6 in | 14.81 yd³ |
Example
A 30 ft by 12 ft gravel area at 4 inches deep is about 120 cubic feet. Dividing by 27 gives about 4.44 cubic yards. With 10% waste, you should plan for about 4.89 cubic yards.
Should You Add Extra Gravel?
Yes. A 5–10% waste allowance is useful for compaction, uneven ground, spreading variation, and small measurement differences. Driveways and base layers may need more if the ground is soft.