How to use this estimate
Measure the formed area rather than relying on the nominal patio size. Take several depth measurements when the base is uneven; small depth differences can change the order substantially. The length and width describe one rectangular slab. For an L-shaped driveway, calculate non-overlapping rectangles separately and add their order volumes.
The calculation
A worked example
A 12 × 10 ft slab, 4 in thick, is 40 ft³ or 1.4815 yd³. With 10% extra, the order estimate is 1.6296 yd³.
Thickness is an input, not a design recommendation. This estimate excludes reinforcing steel, forms, base material, labor, tax, pumping, delivery and supplier minimum-load charges.
Common questions
Does this work for a driveway?
Yes, for volume estimation. Split irregular driveways into rectangles. A contractor must determine the required slab thickness and reinforcement.
Should I round the order up?
Ask the ready-mix supplier about order increments, delivery minimums and an appropriate allowance. The displayed decimals are calculated volume, not a promise of field precision.
References & method
QUIKRETE concrete mix product data. See how we check calculations. Reference links provide context; no supplier endorses this site.