How to calculate a driveway
A driveway needs concrete or asphalt on top and compacted stone below, so plan both volumes.
- Measure the length and the width of the driveway, and add flares where the drive meets the street.
- Pick a thickness: concrete driveways are commonly 4 to 6 inches thick.
- Calculate the concrete or asphalt volume, then repeat the calculation for the 4 to 6 inch stone base.
- Add 5 to 10 percent for waste on the surface, and 10 to 15 percent on the base.
Worked example
For a typical driveway with length 40 ft, width 12 ft, depth 5 in, the volume is 200.00 cubic feet. Divide by 27 for 7.41 cubic yards. With a 10 percent allowance, plan for 8.15 cubic yards.
In concrete, 7.41 cubic yards weighs about 15.00 US tons at a planning value of 4,050 pounds per cubic yard.
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 |
|---|---|---|---|---|
| 20 by 10 ft, 5 in | 83.33 | 3.09 | 3.40 | 6.25 |
| 40 by 12 ft, 5 in | 200.00 | 7.41 | 8.15 | 15.00 |
| 60 by 12 ft, 6 in | 360.00 | 13.33 | 14.67 | 27.00 |
| 80 by 20 ft, 6 in | 800.00 | 29.63 | 32.59 | 60.00 |
Tips
- Heavy trucks need 6 inches or more.
- Ask your contractor whether the quote includes the base and the reinforcing mesh.
- Control joints do not change the volume, but they change the finished look.
Common mistakes to avoid
- Ignoring flares and curves that make the drive wider than it looks on paper.
- Forgetting the stone base volume.
- Using a depth for light patio use on a driveway that carries vehicles.
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 driveway?
Multiply the dimensions in feet and divide by 27. The example above, length 40 ft, width 12 ft, depth 5 in, needs 7.41 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 driveway material weigh?
7.41 cubic yards of concrete weighs about 15.00 US tons as a planning value.