Concrete Slab Calculator

Length, width and thickness go in; cubic yards and bag counts come out. The calculator is aimed at patios, garage floors, walkways and slabs, and the listing adds that it also reports cubic feet and cubic metres, gives 40, 60 and 80 lb bag counts, and takes an adjustable waste factor.

A quick cost estimate section turns that volume into a budget line: enter a price per cubic yard and it returns an estimated total. The dollar amounts shown on the page are outputs of that estimator, driven by the price the user types in.

Supporting sections explain the arithmetic instead of hiding it. They walk through the slab formula, cover how to choose thickness, compare a 10 x 10 ft slab at different thicknesses, and work through the two awkward cases — a slab with a footing and a 20 x 20 ft slab with a perimeter edge. The tool is free and needs no sign-up.