Concrete Costs Per Yard: What Contractors Know That Homeowners Do Not

Concrete is priced per cubic yard, but you think in square feet. Your patio is 20x15 feet, your driveway is 40x12 feet, and you have no idea how many cubic yards that requires or what it should cost. Contractors know exactly how to calculate this, and some of them use that information asymmetry to their advantage. Knowing the math protects you from overpaying. Concrete volume calculation One cubic yard of concrete fills 27 cubic feet (3x3x3). To find how many cubic yards you need: Volume (cubic yards) = Length (ft) x Width (ft) x Thickness (ft) / 27 A 20x15 foot patio at 4 inches thick: 20 x 15 x 0.333 / 27 = 3.70 cubic yards A 40x12 foot driveway at 5 inches thick: 40 x 12 x 0.417 / 27 = 7.41 cubic yards Always round up to the next half yard. Running short mid-pour is a disaster -- you cannot add concrete to a partially set slab without a cold joint that will crack. Order 3.70? Get 4. Order 7.41? Get 8. Most concrete suppliers have a minimum delivery of 1 cubic yard and charge a short