Concrete Driveway Calculator

A typical 2-car driveway is 20 ft wide × 20 ft long × 4 in thick = 400 ft² × (4/12) ft = 133 ft³ ÷ 27 = 4.94 cubic yards. With the recommended 10% overage, order 5.5 cubic yards. Use this calculator to get the exact figure for your dimensions.

Ready-mix concrete costs $130–$180 per cubic yard (2025 US average). A standard single-car driveway (10 ft × 20 ft × 4 in) needs about 2.5 yards — roughly $325–$450 in material. Total installed cost including labour, forming, and finishing typically runs $4–$8 per square foot, or $800–$1,600 for that same single-car driveway.

Rebar (#3 or #4) is recommended for driveways subject to heavy loads or vehicles over 10,000 lbs. For standard residential driveways, welded wire mesh (6×6-W1.4×W1.4) placed in the middle third of the slab is a common and cost-effective alternative. Both reinforcement types do not change concrete volume — calculate your concrete first, then plan reinforcement separately.

Break the driveway into rectangular sections. Calculate the volume for each rectangle using this calculator and add the totals. For curved edges or aprons, use the widest measurement to get a conservative overestimate, or split the curve into several small rectangles and sum them. Always order 5–10% extra to account for irregular subgrade and formwork variation.

Order 5–10% more than your calculated volume. Concrete volume is sensitive to subgrade unevenness — a high spot or low spot of just 1 inch across a 20-foot width adds 0.3 cubic yards of variance. Running short mid-pour is costly (emergency loads, cold joints), while a small amount of leftover can be used for walkway repairs or disposed of.

Use 4,000 PSI (28 MPa) minimum for driveways. In freeze-thaw climates, 4,500 PSI with air entrainment (5–7%) is strongly recommended — the air bubbles give water expansion room during freezing, dramatically reducing surface scaling. 3,000 PSI is only adequate for interior slabs not exposed to weather or vehicle loads.

Concrete reaches initial set in 24–48 hours — you can walk on it. Wait 7 days before driving passenger vehicles on it. Full design strength (typically 4,000 PSI) is reached at 28 days. Avoid heavy vehicles, deicing salts, and pressure washing for the first 30 days. Keep the surface moist during the first week (wet curing) to maximise final strength.