Tile Calculator
How many tiles and boxes you need for a floor or wall, including grout joints and extra for cuts.
Your floor or wall
Filled in with example values. Replace them with your own.
Area to tile
Tile size
Extras
Tiles cut at the edges are partly wasted. On by default; diagonal or patterned layouts usually need more.
Enter how many tiles come in one box, from the label.
Results update as you type.
Result
Tiles to buy: 66 (including 10% extra)
Tiles to buy
66tiles
- Area to tile
- 120 ft²
- Tiles to cover it exactlyBefore extra and rounding
- 60
- Area per tile
- 2 ft²
How it’s calculated
Area to tile
12 ft × 10 ft = 120 ft²
One tile
12 in × 24 in = 2 ft²
Tiles to cover the area
120 ft² ÷ 2 ft² = 60
Plus 10% extra, rounded up
60 × 1.1 = 66 tiles
How the tile calculator works
The calculator divides the area you want to tile by the area one tile covers. If you enter a grout joint, it adds the joint to the tile’s length and width, because each tile and its share of the joint cover a little more than the tile alone.
It then adds your allowance for cuts and breakage and rounds up to whole tiles. If you enter how many tiles come in a box, it rounds up again to whole boxes and tells you how many spare tiles you will have.
The formula
Area per tile = (Tile length + Joint) × (Tile width + Joint)
Tiles = Area to tile ÷ Area per tile
Tiles to buy = Tiles × (1 + Extra % ÷ 100), rounded up
Boxes = Tiles to buy ÷ Tiles per box, rounded up
Tile sizes are usually given in inches or centimetres and rooms in feet or metres, so convert to the same unit first: a 12 × 24 inch tile is 1 × 2 = 2 ft².
Worked example
A kitchen floor is 12 feet by 10 feet, and you have chosen 12 × 24 inch tiles with 10% extra.
- Area to tile: 12 × 10 = 120 ft²
- One tile: 1 ft × 2 ft = 2 ft²
- Tiles to cover the floor: 120 ÷ 2 = 60
- With 10% extra: 60 × 1.1 = 66 tiles
With a 1/8 inch grout joint, each tile covers 12.125 × 24.125 in = 2.03 ft², so the floor takes 59.07 tiles, or 65 tiles with 10% extra. If the tiles come 8 to a box, that is 9 boxes with 7 spare tiles.
Assumptions and limitations
- This is an area-based estimate. It does not plan where cuts fall; the extra allowance covers that.
- The area is a rectangle. Subtract fixed units, islands or other untiled areas yourself.
- No waste percentage is right for every job. The default of 10% is a starting point, not a rule.
- Grout, adhesive and trim pieces are not included.
Frequently asked questions
How much extra tile should I buy?
Enough to cover cuts, breakage and mistakes. Around 10% is a common starting point for a straight layout; diagonal and herringbone patterns, large tiles and rooms with many corners usually waste more. Many people also keep a few spare tiles for future repairs.
Does the grout joint make a difference?
A little. Each tile plus its share of the joint covers slightly more area than the tile alone, so you need slightly fewer tiles. With 12 × 24 inch tiles and a 1/8 inch joint, a 120 ft² floor needs about 59 tiles instead of 60 before any extra.
Can I use this for a wall?
Yes. Enter the wall’s width and height as the length and width. Calculate windows or other areas you will not tile separately and subtract them, or reduce the size you enter.
What about an L-shaped room?
Split it into rectangles, calculate each one, and add the tile counts together before rounding up to boxes.
Should I buy all the tiles at once?
It is usually wise. The colour and shade of tiles can vary between production batches, so tiles bought later may not match. Buying enough at the start, from the same batch, avoids that.