Materials & Quantities

Quantity take-off is where most estimating errors are actually made, and rarely in the geometry. The area of a floor is easy; the waste factor is not, and it depends on the lay pattern, the room shape and how much of one offcut can start the next run. The calculators here make the waste assumption explicit and adjustable rather than burying a single percentage in the arithmetic.

Every page states what it excludes, because an incomplete quantity is more dangerous than an approximate one. Adhesive, fixings, primer, trims and the preparation that a substrate needs are separate lines that a material calculation does not include — and they are consistently the items that turn an accurate take-off into a short delivery.