Flooring
calculator
Room area, plus the waste your layout demands, divided by box coverage, the three-step math that decides whether you finish the floor or finish a box short.
Measuring up a job?
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Why waste isn't optional
Every row ends in a cut, and the offcut rarely fits elsewhere; boards get damaged; patterns need matching. The waste factor covers it: 5% for a simple rectangular room with straight planks, 10% typical, 15% for diagonal layouts, 20% for herringbone or rooms full of alcoves.
Always round up: and keep a box
Boxes only sell whole, and finishing one box short means a store trip that may land in a different production batch (dye lots vary visibly in wood and laminate). Pros order a spare box beyond the calculation for future repairs, a damaged plank years later is fixable only if matching stock exists.
Irregular rooms: split into rectangles, sum the areas with the square footage calculator, and enter the total as one room here. Underlayment follows the same area without the waste factor.
Flooring FAQ
Add 5–10% for straight layouts in simple rooms, 15% for diagonal, up to 20% for herringbone or rooms with many cuts. This covers offcuts, mistakes and damaged boards.
Room area times one-plus-waste, divided by the coverage printed on the box, rounded up. A 192 sq ft room at 10% waste with 20 sq ft boxes needs 11.
Yes, keep at least one full box. Future repairs need planks from a matching dye lot, which stores won't stock forever.
No, underlayment overlaps and trims easily, so the raw room area is enough. Only the visible flooring needs the cutting margin.