Material Quantity Calculator

A takeoff is two separate questions and they get confused constantly. The first is how much material the finished work contains. A slab is length times width times thickness, a wall is perimeter times height less the doors and windows, and a floor is its area divided by the size of one tile. That part is fixed geometry and it is what the middle of this calculator does. The second question is how much you have to buy, which is always more, and that part is a judgment call rather than a fact.

Which is why the waste allowance here is labeled an editable estimate and not a rule. Cuts, breakage, a diagonal layout, a room full of returns and openings, one dropped sheet: all of it lands in that one number, and the right figure is the one your own past jobs show, not the one a website printed. The same goes for paint coverage. We do not fill it in, because it changes with the product, the surface and how it is being put on, and a figure typed in by us would be read as a specification. Take it off the tin.

The mistake worth naming: ordering to the exact geometry because the arithmetic looked precise. A number with two decimal places is not more certain than the tape measure it came from. Round up to whole sheets, whole boxes and whatever increment your supplier actually sells, and check what you ordered against what you used afterwards. Zeus records materials and expenses against the job they were bought for, so that check takes a minute instead of an evening.