Concrete Driveway Calculator
This concrete driveway calculator estimates the driveway concrete volume from the length, width, and slab thickness. It returns cubic yards, cubic feet, weight, and bag counts, and it has an optional second thickness so you can model a driveway that slopes or thickens at the apron. It is a fast concrete driveway estimator for any single- or double-car drive.
How to use this calculator
- Enter the driveway length and width.
- Set the thickness — 4 inches for cars, 5–6 inches for trucks and RVs.
- Add a second thickness only if the slab slopes or thickens at one end.
- Choose a waste allowance and read the cubic-yard total for ready-mix.
The formula
A driveway is a large slab: length × width × thickness ÷ 27 for cubic yards. If you enter a second thickness, the calculator uses the average of the two:
Cubic yards = (Length ft × Width ft × Thickness ft) ÷ 27
Worked example. A 20 ft × 10 ft driveway at 5 inches thick: 5 inches is 0.417 ft, so 20 × 10 × 0.417 = 83.3 cubic feet, or 3.09 cubic yards. Slope it from 5 to 6 inches and the average 5.5 inches gives about 3.40 cubic yards.
Frequently asked questions
How much concrete do I need for a driveway?
Multiply length × width × thickness in feet, then divide by 27 for cubic yards. A 20 × 10 ft driveway at 5 inches thick is about 3.1 cubic yards before waste.
How thick should a concrete driveway be?
Four inches is the minimum for cars; use 5–6 inches for trucks, RVs, or frequent heavy loads. Thicker slabs with rebar resist cracking far better.
How many yards of concrete for a 2-car driveway?
A typical 20 × 20 ft two-car driveway at 5 inches thick needs about 6.2 cubic yards. Add 10% waste and round up when ordering ready-mix.
Does a driveway need rebar or wire mesh?
Yes — reinforcement and properly spaced control joints are what keep a driveway from cracking under vehicle weight and seasonal ground movement.