Tile Count Calculator
Enter your room and tile dimensions to get the tile — and box — count for the job, with a waste allowance built in.
Tiles needed
How the count is calculated
The calculator divides your room's area by a single tile's area to get the exact tile count with zero waste, then adds your waste percentage and rounds up to a whole tile — you can never buy a fraction of a tile, so the last partial tile always rounds up. If you enter a tiles-per-box figure, the same rounding-up happens again for the box count.
Measure the room at its widest points and round up to the nearest inch before you plug in the numbers; it's far better to have a few spare tiles left over than to be one short mid-job.
Frequently Asked Questions
How much waste allowance should I add?
10% is the standard baseline for a simple straight (grid) layout on a rectangular room. Bump it up to 15% or more for a diagonal layout, a herringbone or brick-joint pattern, a room with lots of corners and cutouts, or your first time cutting tile — extra breakage and mis-cuts are normal.
Does this account for grout lines?
Not directly — the calculation is based on the tile's own dimensions, and grout lines are thin enough (typically 1/16 to 1/4 inch) that they have a negligible effect on the tile count for most rooms. The waste allowance comfortably covers this small difference.
Why buy tiles by the box instead of the exact count?
Tile is almost always sold by the box, and mixing lots/dye batches can produce a visible color shift. Buying in full boxes — and a little over your exact need — gives you matching spares for future repairs without hunting down the same batch later, which is often impossible once a run sells out.
What if my room isn't a simple rectangle?
Split the room into rectangular sections, run the calculator for each one, and add the tile counts together (or add the areas before dividing by the tile size). For an L-shaped or irregular room, a slightly higher waste allowance also helps absorb the extra cuts around the corners.
Planning estimate only. Re-measure an irregular room in sections and always round the final tile and box counts up, not down.