A concrete driveway is fundamentally different from a patio or shed slab. Driveways must handle the weight of vehicles (3,000 to 6,000 pounds per car), resist tire abrasion, withstand de-icing salt in cold climates, and look presentable from the street for decades. These demands require thicker slabs, stronger concrete, and more careful base preparation.
The standard thickness for a residential driveway is 6 inches, not the 4 inches used for patios. This extra 2 inches increases concrete volume by 50 percent but is essential for supporting repeated vehicle loads without cracking. Some municipalities require 6 inches by code, and most concrete professionals refuse to pour a driveway thinner than 5 inches.
A typical single-car driveway measures 20 feet long by 10 feet wide (200 square feet). At 6 inches thick, that requires 3.7 cubic yards before waste. With 10 percent waste, order 4.1 yards. A double-wide driveway (20 x 20) needs 8.1 yards. These are ready-mix truck quantities. Bagged concrete is impractical for any driveway project.
Drainage is the hidden factor that separates driveways that last 30 years from those that crack in 5. The slab should slope away from the garage at a minimum of 1/8 inch per foot (a 20-foot driveway drops 2.5 inches from garage to street). Without proper slope, water pools against the garage foundation and freeze-thaw cycles destroy the concrete edges.
A standard single-car driveway (20x10 feet, 6 inches thick) requires approximately 4.1 cubic yards of concrete including waste.
Volume for a 20x10 driveway at 6 inches: 20 x 10 x (6/12) = 100 cubic feet, divided by 27 = 3.70 cubic yards. With 10 percent waste: 4.07 yards. For a wider driveway (20x20), double the quantity: 7.41 yards with waste.
Specify 4,500 PSI concrete for driveways (versus 4,000 PSI for patios). The higher strength handles vehicle loads and resists salt damage better. In freeze-thaw climates, request air-entrained concrete, which contains microscopic air bubbles that give water room to expand when it freezes inside the slab. Air entrainment adds minimal cost but dramatically extends driveway life in cold regions.
Rebar reinforcement is standard for driveways: #4 rebar (1/2 inch diameter) on 18-inch centers in both directions, placed on chairs so it sits in the lower third of the slab. This reinforcement grid holds the slab together if the subgrade shifts or settles, preventing the two-piece cracking pattern that destroys unreinforced driveway slabs.
Use this calculator for any residential driveway project, whether you are replacing an existing driveway, extending one, or pouring new. It covers single-car (10 to 12 feet wide), double-car (18 to 24 feet wide), and extended driveways with turnarounds. For driveways with curves or flared entries, approximate each section as a rectangle, add the volumes, and include 15 percent waste instead of 10 percent for the additional forming complexity.