How the flooring calculator works
It multiplies the room’s length by its width, adds a waste allowance for cuts and the end pieces of each row, and divides by the coverage of one box. Boxes are rounded up, since stores won’t sell part of one.
The formula
floor area = length × width
boxes = floor area × (1 + waste %) ÷ coverage per box, rounded up
Tips
- 10% waste works for most rectangular rooms laid parallel to the walls. Use 15% for diagonal layouts or rooms with lots of jogs, closets and doorways.
- L-shaped room? Split it into two rectangles, run each one, and add the boxes together.
- Buy one extra box and keep it. If a plank gets damaged in five years, the exact colour run may no longer be sold.
- Acclimatize the flooring in the room for the time the manufacturer recommends before installing, especially in winter when indoor air is dry.