Concrete Calculator: Slabs

How much concrete, and how many bags. Pick a slab, a footing, a column or a flight of stairs, type the dimensions, and read the answer in cubic yards, cubic metres and cubic feet at once — with the bag count for 40, 60 and 80 lb bags beside it. EVERY BOX SAYS ITS OWN UNIT A slab is twelve feet long and four inches deep at the same moment, and no app should make you convert one into the other. Each box is labelled with the unit it wants. Type 12' 6", 12 6, 12.5 or 4 1/2 — all of them mean the same thing here, and a comma decimal works as well as a point. WASTE, ADDED IN THE RIGHT ORDER Spillage, an uneven subgrade and over-excavation are real, so the allowance goes on the volume before the bags are counted, never after. Bags always round up, because merchants sell whole ones. STAIRS DONE PROPERLY A flight poured solid is a staircase prism, not a box and not half of one: each step sits on…