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Tile Calculator

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Enter your floor or wall area and tile size to find exactly how many tiles you need, with a waste allowance for cuts and breakage built in.

Tile Calculator

Live
Tiles needed
132
Boxes needed
14
Coverage per tile
1.00 sq ft
A 10% waste allowance is standard for straight-lay patterns; diagonal or complex patterns often need 15-20%.

The formula

Tile coverage (sq ft) = (Length x Width in inches) / 144 Tiles needed = ceiling( (Area x (1 + Waste %)) / Tile coverage )
Example

A 120 sq ft floor with 12x12 in tiles (1 sq ft each) and 10% waste: 120 x 1.10 = 132 sq ft needed, so 132 tiles - at 10 tiles per box, that's 14 boxes (rounding up).

Step-by-step guide

  1. Measure the total area you're tiling, in square feet.
  2. Enter your tile's dimensions in inches.
  3. Enter tiles per box if you want a box count, and adjust the waste percentage for your layout pattern.
  4. Always round up - buy the full number of boxes shown, and ideally keep a couple of spare tiles for future repairs.

How much waste allowance do you really need?

A straightforward straight-lay pattern in a mostly rectangular room can often get by with 10% waste. A diagonal layout, a room with lots of corners and cutouts (like a bathroom with a toilet and vanity), or a herringbone or other complex pattern can easily need 15-20% extra due to the higher number of angled cuts. Large-format tiles also tend to waste more per cut than small ones, since a single miscut wastes a bigger, more expensive piece.

Common mistakes

Buying the exact tile count with no waste allowance - even careful installers lose some tiles to cuts, breakage, and future repairs.
Buying tiles from different production lots (dye lots) later for a repair - color can vary noticeably between lots, so buying a few extra up front avoids a mismatch down the line.

Frequently asked questions

Should I buy extra tiles for future repairs?

Yes - keeping a small stash (5-10 extra tiles) from the same dye lot as your installation makes future repairs much easier, since matching an exact color and pattern years later can be difficult or impossible.

Does grout line width affect how many tiles I need?

Only slightly for most residential grout lines (1/8 to 1/4 inch) - the effect on total tile count is small enough that this calculator doesn't need to account for it separately, especially with the waste allowance already built in.

What's a typical waste percentage for a bathroom?

Bathrooms often have more cuts around fixtures than a simple rectangular room, so many installers plan for 15% waste there instead of the standard 10%.

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