How much concrete is a 20×40 driveway?
A 20-by-40-foot driveway covers 800 square feet. At the standard 5-inch thickness that's about 12.35 cubic yards of concrete before waste, or roughly 13.58 yards once you add a 10% allowance. At about 13.58 cubic yards you are into multi-truck territory, so line up site access and timing before you schedule delivery. The calculator above is pre-filled to these dimensions; change the thickness or price to match your job.
Concrete for a 20×40 driveway by thickness
| Thickness | Concrete to order | 80 lb bags | Material cost |
|---|---|---|---|
| 5″ (standard) | 13.58 yd³ | 612 | $2,173 |
| 6″ | 16.30 yd³ | 734 | $2,607 |
| 8″ | 21.73 yd³ | 978 | $3,477 |
Material cost at $160/yd³ ready-mix, before delivery fees. Cost data updated June 2026.
Common questions
How many yards of concrete for a 20x40 driveway?
A 20x40 driveway at 5 inches thick needs about 12.35 cubic yards before waste. Add 5-10% extra so you don't come up short. Change the thickness in the calculator above to see how it affects the total.
How many bags of concrete for a 20x40 driveway?
At 5 inches thick that's roughly 612 eighty-pound bags with a 10% allowance. Past about 1 cubic yard (around 45 bags), ready-mix delivery is usually cheaper and far less work than mixing bags by hand.
What does a 20x40 driveway cost?
Material alone is a small share of the total. Installed, driveways this size run a wide range depending on thickness, finish, site prep, and region. Use the calculator's installed-cost range as a ballpark, then compare local quotes for a real price.