Example 1
- 10 ft × 12 ft
- 12 × 12 in
- waste 10%
132 tiles
How many 12×12 in tiles for a 10×12 ft floor at 10%? 120×1.10 = 132 tiles.
Tile Calculator
Enter the length and the width of a rectangular floor in feet, and the tile size in inches. The area is length times width. A 10 by 12 ft floor is 120 ft². With 12×12 in tiles and 10% waste that is 132 tiles.When meters are selected at the top of the page, enter the length and the width in meters and the tile size in centimeters. The result is still a number of tiles.
Results
Enter the floor length and width, then the tile size. The result appears below.
The calculator tells you how many tiles to buy. It uses the floor length and width, or an area you already know, plus one tile’s size and an allowance for cuts. When you enter tiles per box, the box count rounds up. Tile adhesive is on the tile adhesive calculator. The floor area calculator turns length and width into area in the unit selected at the top of the page. Read more in the article on how many tiles to buy.
How the results are calculated
Floor120.00 ft²
Tile12×12 in
Waste10%
Tiles132 tiles
The tile calculator tells you how many pieces to buy for a floor or a wall. It divides the area by one tile, adds the waste, and rounds the number of tiles up. When you enter openings, it subtracts them from the area before that division. The area of one tile comes from the width and the height. With feet selected, those sides are in inches. With meters selected, they are in centimeters. If you enter your own tile area, the calculator uses that number. A straight layout suggests 10% waste. Diagonal and herringbone suggest 15%. When the waste field is empty, changing the layout inserts the percent for that layout. A number you enter stays, unless it matches the last suggestion. Changing the layout then replaces it. When you enter tiles per box, the box count rounds up as well.
A 10 by 12 ft floor is 120.00 ft². A 12×12 in tile covers 1 ft², so 10% waste comes to 132 tiles. A 5 by 8 ft floor is 40.00 ft², and the same tile at 10% comes to 44 tiles. A 12 by 15 ft floor is 180.00 ft². A 12×24 in tile covers 2 ft², so 15% waste comes to 104 tiles. At 10 tiles per box that is 11 boxes.
Enter the length and the width of the floor, then the width and the height of the tile. The waste field is next to the layout list. Openings, a custom tile area, tiles per box, and price are in the additional options, and you can leave them empty. You can enter 7.2 or 7,2. The calculator reads both as the same number. If you already know the area of one tile, including the grout, enter that custom area. The calculator ignores the width and the height. Choose “I know the area” when you already know the floor area in the unit selected at the top of the page.
Tile adhesive is on a separate page. That page uses the floor area and the coverage printed on the bag. Paint and plaster are on separate pages.
The store sells whole tiles and whole boxes. A figure of 103.5 before rounding means at least 104 tiles. If a box holds ten tiles, you buy full boxes. A large tile, a diagonal layout, and herringbone need more waste than a straight layout. The calculator does not subtract a 2 mm grout joint. The waste allowance usually covers those cuts.
With feet selected, enter a length of 10 ft, a width of 12 ft, a 12 by 12 in tile, and 10% waste. The result is 132 tiles. If you already know the area in square feet, choose “I know the area”, enter 120 ft², a 12 by 12 in tile, and 10% waste. The result is 132 tiles.
How to use this calculator
- Enter the length and the width of a rectangular floor. A 10 by 12 ft floor is 120.00 ft². With 12×12 in tiles and 10% waste the result is 132 tiles. If feet are selected and you already know the area in square feet, choose “I know the area” and enter 120 ft², for example.
- Pick a size or enter the tile width and the height. With feet selected, those sides are in inches. With meters selected, they are in centimeters. A straight layout suggests 10% waste. Diagonal and herringbone suggest 15%. When the waste field is empty, changing the layout inserts the percent for that layout. A number you enter stays, unless it matches the last suggestion. Changing the layout then replaces it.
- You can enter a custom tile area, the area of openings, tiles per box, and a price. These fields can stay empty.
- Click “Calculate”. The calculator rounds the number of tiles up, and it rounds the box count up when you enter tiles per box.
- Adhesive is on a separate page.
Formula
Tiles = ⌈ ((area − openings) / tile_area) × (1 + waste/100) ⌉
With feet selected, tile area in ft² is (width_in × height_in) / 144. Straight layout starts at 10% waste; diagonal and herringbone start at 15%. Boxes = ⌈ tiles / tiles_per_box ⌉.
A 10 × 12 ft floor is 120 ft². A 12×12 in tile covers 1 ft². At 10% waste: 120 × 1.10 = 132 tiles. This is a shopping estimate, not a store quote.
12×12 tiles on a 10 by 12 ft floor
The calculator divides the area by one tile, adds the waste, and rounds the number of tiles up. A 10 by 12 ft floor is 120.00 ft². With 12×12 in tiles and 10% waste the result is 132 tiles.
- ft²
- This is the area to be tiled. A 10 by 12 ft floor is 120.00 ft². With 12×12 in tiles and 10% waste, the result is 132 tiles. A 5 by 8 ft floor is 40.00 ft² and needs 44 of the same tiles.
- 12×12
- The tile from the first example, measured in inches. One tile covers 1 ft². 120 × 1.10 = 132.
- Waste
- Percent added before rounding. Straight layout starts at 10%; diagonal and herringbone start at 15%. On 120 ft² with 12×12 in tiles and 10% waste the result is 132 tiles.
- Openings
- Area subtracted before the division (hearth, niche). When openings exceed the floor, the result is zero tiles.
- Box
- A full package. At 104 tiles and 10 per box you buy 11 boxes because the box count rounds up.
Examples
Example 2
- 5 ft × 8 ft
- 12 × 12 in
- waste 10%
44 tiles
5×8 ft floor, 12×12 in tile, 10% waste → 44 tiles.
Example 3
- 12 ft × 15 ft
- 12 × 24 in
- waste 15%
- 10 tiles per box
104 tiles
11 full boxes
12×15 ft, 12×24 in tile, 15% → 104 tiles (11 boxes of 10).
Related calculators
Frequently asked questions
How do I calculate how many tiles I need from area and tile size?
Divide net area by one tile’s area, multiply by (1 + waste/100), and round up. A 10×12 ft floor with 12×12 in tiles at 10% waste → 132 tiles.
How many 12×12 tiles for 100 square feet?
With 10% waste: 110 tiles (100 × 1.10). Without waste the count is 100, because each 12×12 in tile covers 1 ft².
Is this a tile adhesive or grout calculator?
No. Here you get a tile count (and boxes). Tile adhesive lives on a separate construction card.
Does the result guarantee I will not need another box?
No. It is an estimate with the waste you choose. Cuts, out-of-square walls, and pattern layouts can need more tiles.
Is this a free tile calculator?
Yes. Enter area or room size, tile size, and waste, and you see the count at once. No account required.
How is the tile count calculated?
The calculator uses net area (after openings), divides by one tile, multiplies by (1 + waste/100), and rounds up. On a 10 by 12 ft floor with 12×12 in tiles and 10% waste the result is 132 tiles.
What waste should I use for straight, diagonal, and herringbone?
Straight layout suggests 10%. Diagonal and herringbone suggest 15%. When waste is empty, changing the layout inserts that percent. A different number you enter stays, unless it matches the last suggestion.
Should I subtract grout joints from the area?
No. The calculator uses one tile’s area plus waste. A 2 mm joint barely changes the count, and stores sell whole tiles. If you know the piece area including grout, enter it as a custom tile area.
How do boxes and price work?
When you enter tiles per box, the box count rounds up. On a 12 by 15 ft floor with 12×24 in tiles, 15% waste, and 10 tiles per box the result is 104 tiles, or 11 boxes. Price uses full boxes or whole tiles.
How is Room size different from I know the area?
Room size multiplies length by width. I know the area uses a figure you already have. Tile size and waste work the same in both modes.
Is the formula the same for walls and floors?
Yes. The calculator divides area by one tile and adds waste. Openings are subtracted only when you enter them.
What do openings and custom tile area do?
Openings are subtracted before the division. Custom tile area replaces width and height when you already know one piece’s coverage (including grout, for example).
Does the result round up?
Yes. Stores sell whole tiles. 36.67 becomes 37. 44.2 becomes 45. Boxes round up too.
Where do I calculate adhesive after the tile count?
On the tile adhesive page. Enter the area and the coverage from the bag or trowel notch. Floor area can also be computed on the floor area page.
Does the result guarantee I will not need to buy more?
No. It is an estimate from the numbers you enter. Large formats, niches, and uneven walls may need more waste. It is not a store quote.
Sources
Tile area comes from the size you enter. Below are the definition of area and the NIST guide to SI units.
Page updated October 12, 2026.