Flooring Planks
Calculator

It divides your room's floor area by the area of a single plank, then adds a waste factor (typically 5-10% for straight-lay patterns, more for diagonal layouts) to account for cuts at edges and around obstacles.

Cutting planks to fit at walls, doorways, and around corners always produces some unusable offcuts, and diagonal or herringbone patterns waste significantly more material than a straight parallel layout, which is why waste factors are higher for those patterns.

Yes, a simple rectangular room with no obstacles can often get by with 5% extra, while an irregularly shaped room, one with many closets or nooks, or a complex layout pattern should use 10-15% to avoid running short of a specific dye lot.

Yes, whenever possible, because planks are manufactured in dye lots and color can vary subtly between production runs. Buying everything you need upfront, plus your waste buffer, avoids a mismatched patch if you have to reorder later.

Wider, longer planks cover more area per piece but often come in boxes with a fixed square footage regardless of plank size, so the calculator's job is really converting your needed area into the number of boxes, since that's how flooring is actually sold.