How it works
Divide room area by tile area to get a raw tile count, add a wastage allowance for cuts and breakage, then round up — you can't buy part of a tile, and running short mid-job means a delayed, possibly mismatched, second order.
Worked example
A 10 ft × 10 ft room, 12 in × 12 in tiles, 10 per box, 10% wastage.
- Room area: 10 × 10 = 100 sq ft.
- Tile area: 12 × 12 = 144 sq in = 1 sq ft.
- Raw count: 100 ÷ 1 = 100 tiles.
- With 10% wastage: 100 × 1.10 = 110 tiles.
- Boxes: 110 ÷ 10 = 11 boxes.
You'd need 110 tiles, or 11 boxes.
Common questions
How much wastage should I allow?
10% is a common default for a straightforward grid layout. A diagonal layout, herringbone pattern, or a room with many alcoves and corners can easily need 15% or more, since every cut edge risks a wasted offcut.
Should I buy exactly the boxes this calculator says?
It's worth buying from the same production batch or dye lot where possible, since tile color can vary slightly between batches — buying a few boxes over what's calculated gives room for breakage and future repairs without a batch mismatch.
Does this account for grout lines?
No — grout lines are thin enough relative to most tile sizes that they don't meaningfully change the tile count, and grout itself is bought separately based on joint width and depth, not tile count.