Concrete Driveway Calculator
Work out how much concrete a driveway needs — the ready-mix volume to order, the gravel sub-base beneath it, and the cost at your price per cubic yard.
A driveway is a slab with a job to do: it carries vehicles, so thickness and the sub-base matter as much as volume. This calculator gives you the ready-mix to order, the gravel beneath it, and the cost — from four measurements.
For the slab alone, without the driveway specifics, use the concrete slab calculator.
Your results
Enter your measurements and press Calculate.
Quantities are rounded up to whole tiles, planks, boxes or bags, after the wastage allowance. Cost appears only when you enter a price.
Formula
All lengths are converted to a single unit before the calculation: 1 ft = 0.3048 m, 1 in = 25.4 mm, 1 ft² = 0.09290304 m², 1 yd² = 9 ft². Material quantities are rounded up — you cannot buy part of a tile, plank or bag.
How to use this calculator
- Measure the driveway length and width.
- Choose the concrete thickness — 4 in for cars, 6 in for heavier vehicles.
- Set the sub-base depth (usually 4 in of gravel).
- Add a ready-mix price per cubic yard if you want a cost estimate.
Worked example
| Driveway | 20 ft × 12 ft × 4 in thick |
|---|---|
| Area | 20 × 12 = 240 ft² |
| Concrete volume | 240 × (4 ÷ 12) = 80 ft³ = 2.96 yd³ |
| Ready-mix with 10% wastage | 80 × 1.10 = 88 ft³ = 3.26 yd³ |
| Sub-base (4 in gravel) | 240 × (4 ÷ 12) = 80 ft³ = 2.96 yd³ |
| Cost at $150 per yd³ | 3.26 × $150 = $489 |
Check it by hand: every step above uses the formula in the box. If your numbers match the example inputs but the calculator gives a different answer, please report it via the contact page.
Frequently asked questions
How thick should a concrete driveway be?
4 in (100 mm) is standard for cars. Use 6 in (150 mm) if the driveway carries vans, trucks or caravans. Thickness matters more than strength grade for a driveway that lasts.
Do I need a gravel sub-base under a driveway?
Yes. A 4 in layer of compacted gravel (sub-base) spreads the load, drains water and stops the slab sinking unevenly. This calculator works out its volume too — order it with the same length and width.
How much concrete do I need for a driveway?
Multiply length × width × thickness, then add 10%. A single-car driveway (20 × 12 ft, 4 in thick) needs about 3.26 yd³ of ready-mix. Larger driveways are almost always cheaper as ready-mix than as bags.
How long before I can drive on a new concrete driveway?
Keep vehicles off for at least 7 days, ideally 14. The concrete reaches most of its strength in 7 days and full strength in about 28 days.
Related calculators
Estimates only. Results are for planning. Measure twice, confirm box coverage and tile sizes on the packaging you buy, and follow the manufacturer's instructions. See the disclaimer.