Why account for technical waste
Installing flooring or tile always involves cuts and offcuts — known as technical waste. The market standard is 8% to 12%, and this calculator uses 10% as the default (adjustable).
Formula
Boxes = ⌈(room area × (1 + waste%)) ÷ area per box⌉, always rounded up (you can't buy half a box).
How to find "area per box"
This information is on the product packaging or spec sheet, usually expressed in m²/box or sq ft/box.
Tip
For irregularly shaped rooms or lots of cuts (like bathrooms with many corners), consider using a higher waste factor, 12% to 15%.
Frequently asked questions
What's the ideal waste percentage?
10% is standard, but rooms with lots of cuts (bathrooms, kitchens with many fixtures) may need 12-15%.
Where do I find the area covered per box?
On the flooring/tile packaging or the manufacturer's spec sheet, usually in m²/box.
Is the result always rounded up?
Yes, because you can't buy a fraction of a box — rounding down would leave you short on material.
Does this work for porcelain tile and ceramic tile?
Yes, it works for any flooring or tile sold in boxes with a known coverage area.