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Tile Calculator
Enter the size of the floor or wall and the size of your tile to see how many tiles and boxes to buy. The calculator accounts for the grout gap and adds a waste allowance for cuts and breakage.
- Boxes to buy
- 9
- Area to tile
- 80 ft²
- Area including waste
- 88 ft²
- Tile cost
- $270.00
Saved setups
Save a set of inputs you reuse — your usual rate, your loan, your room sizes — and load it back in one tap.
Your recent calculations
Results you calculate here are kept on this device so you can come back to them.
Formula
How to use it
- Enter the area’s length and width.
- Enter the tile’s length and width in inches, and the grout gap.
- Choose a waste allowance to suit your layout.
- Enter tiles per box and the box price to get boxes and cost.
Worked examples
A 10 × 8 ft floor in 12 × 12 in tile with no grout gap and 10% waste, 10 tiles per box at $30
- Area to tile
- 80 ft²
- Area including waste
- 88 ft²
- Tiles needed
- 88
- Boxes to buy
- 9
- Tile cost
- $270.00
The same floor with a 1/8 in grout gap
- Tiles needed
- 87
- Boxes to buy
- 9
- Tile cost
- $270.00
A 5 × 8 ft bathroom floor in 6 × 6 in tile, 20 per box at $25
- Tiles needed
- 176
- Boxes to buy
- 9
- Tile cost
- $225.00
How much waste to allow
10% is standard for a straight grid in a simple room. Use 15% for diagonal, herringbone or offset patterns and for rooms with many corners. Large-format tile in a small room can waste more, because each cut uses up most of a tile.
Buy everything at once and keep a few spares. Tile is made in lots, and a later batch may differ slightly in shade and size.
Nominal versus actual size
A tile sold as 12 × 12 in is often slightly smaller, around 11¾ in, so that tile plus grout line makes 12 in. If you enter the nominal size, set the grout gap to 0 to avoid counting the joint twice.
Questions people ask
How many 12×12 tiles do I need for 80 square feet?
80 tiles to cover the area exactly, or 88 with 10% waste. At 10 tiles per box that is 9 boxes.
How many tiles are in a square foot?
One 12 × 12 in tile, four 6 × 6 in tiles, or eight 3 × 6 in subway tiles, ignoring grout lines.
How do I work out tile for a wall with a window?
Calculate the full wall, then subtract the window area from the length × width before adding waste. For small openings many tilers ignore the deduction and treat it as extra waste allowance.