TidyToolsHow many boxes of flooring or tile do I need?
Start with the floor area — length times width. But you should never buy exactly that, because every job wastes some material: tiles and planks get cut to fit at the edges, some crack, and pattern-matching leaves offcuts. That's what the waste allowance is for. Add 10% for a simple square room, 15% for diagonal layouts or lots of corners, and up to 20% for herringbone or busy patterns. It's also smart to keep a spare box for future repairs.
Once you know the area including waste, divide by the coverage printed on each box (in m² or sq ft) and round up — you can only buy whole boxes. This calculator does the maths and, if you enter a price per box, estimates the total cost too.
A worked example
A 5 m × 4 m room is 20 m². With a 10% waste allowance you plan for 22 m². If each box covers 2 m², that's 11 boxes. At £30 a box, budget around £330 — plus keep one box back for repairs down the line.
Tips
- Buy the same batch — colours can vary slightly between production runs, so get it all at once.
- Keep a spare box sealed for future repairs; discontinued lines are hard to match.
- Increase waste for diagonal or herringbone layouts and rooms with lots of alcoves.
- Don't forget underlay, adhesive, grout, and edge trims.
Frequently asked questions
How much waste should I add for flooring?
Around 10% for a straight layout in a simple room, 15% for diagonal or many corners, and up to 20% for herringbone and complex patterns.
How do I convert area to boxes?
Divide the area (including waste) by the coverage per box, then round up to the next whole box since you can't buy part of one.
Should I buy an extra box?
Yes — keeping one spare box from the same batch makes future repairs far easier, as colours vary between production runs and lines get discontinued.