How the flooring calculation works
Two multipliers stand between the room's area and the receipt:
Boxes = ⌈ area × (1 + waste%) ÷ box coverage ⌉
The waste percentage absorbs cut-offs at walls, defective planks, and — the silent killer — stagger requirements that force short pieces into the bin. Standard allowances: 10% for simple rectangular rooms, 15% for rooms with many jogs, closets or diagonal layouts. You always round up to a whole box; most retailers will not split them, and dye-lot matching argues against ordering the remainder later anyway.
Worked example
A 16 × 12 ft room is 192 ft². With 10% waste you need material for 211 ft². Boxes covering 23.8 ft² give 8.87 boxes → buy 9 boxes, about 214 ft² of plank. At $45 per box the floor is $405 in material. Buy one extra box if the product might be discontinued — five years later, a single damaged plank replacement is worth far more than the $45.
Box coverage is not marketing fluff
The printed ft² per box is real and varies wildly by product: luxury vinyl plank boxes run 17–30 ft², laminate 13–25. Always read the box, not the product family. And measure the room at the widest points, then subtract nothing for built-ins you will floor around — cutting around them consumes the waste allowance, which is exactly why it exists.