Concrete Calculator estimates finished concrete volume (in cubic yards, feet or meters), whole bags and optional material cost for slabs, footings, walls, columns, hollow cylinders, stairs and ramps. It has a reserve setting, a bag-yield selector with presets from the QUIKRETE No.1101 data sheet, user-entered prices, share, print, copy and download of results, and a 3D preview.
The page says 'Free to use' and 'No account needed.' It runs in the browser with no app. Estimates are geometry only and exclude delivery, pumping, tax and design work. The page includes a note that it is not affiliated with QUIKRETE.
People planning slabs, footings, walls, columns, stairs and ramps need finished volume, whole bag counts and optional material cost before they buy. Concrete Calculator is a free geometry estimator for that.