How to calculate a gravel driveway
A gravel drive is built in layers: a coarse base, then a finer surface, and each layer needs its own order.
- Measure the drive length and width.
- Plan a total depth of 4 to 8 inches, split into a base layer and a surface layer.
- Calculate each layer, and add 10 to 15 percent for compaction.
- Ask the supplier for tons as well as yards.
Worked example
For a typical gravel driveway with length 50 ft, width 12 ft, depth 6 in, the volume is 300.00 cubic feet. Divide by 27 for 11.11 cubic yards. With a 10 percent allowance, plan for 12.22 cubic yards.
In gravel, 11.11 cubic yards weighs about 15.56 US tons at a planning value of 2,800 pounds per cubic yard.
Gravel Driveway sizes and quantities
These common sizes are calculated with the same formula as the tool above, so you can find your number quickly.
| Size | Cubic feet | Cubic yards | With 10 percent extra | US tons |
|---|---|---|---|---|
| 30 by 10 ft, 4 in | 100.00 | 3.70 | 4.07 | 5.19 |
| 50 by 12 ft, 6 in | 300.00 | 11.11 | 12.22 | 15.56 |
| 100 by 12 ft, 6 in | 600.00 | 22.22 | 24.44 | 31.11 |
| 150 by 14 ft, 8 in | 1,400.00 | 51.85 | 57.04 | 72.59 |
Tips
- Crowned drives shed water better than flat ones.
- Edging helps keep the gravel from spreading.
- Fabric under the base prevents mixing with soft soil.
Common mistakes to avoid
- Using only one thin layer on a soft subgrade.
- Ignoring compaction.
- Choosing round stone that will not lock together.
These figures are planning estimates. Real material varies in moisture, size, and compaction, so confirm weights and order quantities with your supplier.
Frequently asked questions
How many cubic yards do I need for a gravel driveway?
Multiply the dimensions in feet and divide by 27. The example above, length 50 ft, width 12 ft, depth 6 in, needs 11.11 cubic yards before waste.
How much extra should I order?
Add 5 to 10 percent for waste. Add more if the ground is uneven or the material is loose.
Can I enter inches and feet together?
Yes. Each box has its own unit selector, so you can mix feet and inches.
How much does gravel driveway material weigh?
11.11 cubic yards of gravel weighs about 15.56 US tons as a planning value.