Estimate concrete volume in cubic feet, yards, and meters, plus bags required.
Volume = length × width × depth; cubic yards = cubic feet / 27; bags = volume / bag yield.
A 10 ft × 10 ft slab 4 inches deep needs about 1.23 cubic yards, or roughly 55 80-lb bags.
A 4-inch slab is standard for patios and walkways; driveways often use 5–6 inches.
The calculator divides the volume by the yield per bag (e.g., 0.6 cu ft for an 80-lb bag).
Yes. Add 5–10% for spillage and uneven subgrade.