How many tiles do I need?
Working out how many tiles to buy starts with two numbers: the area you're covering and the size of a single tile. Measure the length and width of the floor or wall, multiply them for the area, then divide by the area one tile covers and round up — plus a little extra for cuts and breakage.
A 12×12 in tile covers exactly 1 sq ft, so it's an easy check: a 100 sq ft floor needs about 100 tiles before waste. Change the tile size and the count changes with it — the calculator above does the division and rounding the instant you type.
Tiles, boxes or square feet
Tile is priced a few different ways. Buying loose or by the piece? Keep Sold by on Tile and enter the tile size. Buying by the box? Add your tiles per box for a box count too, or switch to Box and enter the coverage printed on the carton. Some large-format and stone tile is sold by area — switch to Sq ft for that.
Worked example
A bathroom floor 8 ft by 6 ft, tiled in 12×24 in porcelain (each tile covers 2 sq ft):
8 × 6 = 48 sq ft. 48 ÷ 2 = 24 tiles, and with ~10% waste you'd order 27 tiles.
How much extra for waste?
- 10% — standard straight lay in a simple rectangular room
- 10–15% — rooms with lots of cuts around fixtures, niches or corners
- 15%+ — diagonal, herringbone or mosaic patterns
Tap a percentage into the “+ Add waste calc” buffer in the project total and it's added on top of your order.
Common tile sizes
These are the sizes the calculator starts from when you pick a type; your tile may differ, so type the exact size into Tile size.
| Tile | Typical size | Covers |
|---|---|---|
| Ceramic | 12 × 12 in | 1.0 sq ft |
| Porcelain | 12 × 24 in | 2.0 sq ft |
| Mosaic sheet | 12 × 12 in | 1.0 sq ft |
| Natural stone | 12 × 12 in | 1.0 sq ft |
| Subway | 3 × 6 in | 0.125 sq ft |
Tiling a wall or backsplash? Enter its height and width the same way — the math is identical to a floor.
Common questions
How many tiles do I need?
Measure the length and width of the area and multiply them for the area in square feet. Work out the area a single tile covers (tile width × height ÷ 144 for inches), divide the area by that and round up, then add about 10% for cuts and breakage. The calculator above does all of this instantly from your tile size and totals several areas at once.
How do I work out tiles from tile size?
A 12×12 in tile covers 1 sq ft, so a 100 sq ft floor needs about 100 tiles before waste. A 12×24 in tile covers 2 sq ft, so the same floor needs about 50. Enter your exact tile size and the calculator divides and rounds up for you, in inches or centimetres.
How many boxes of tile do I need?
Divide your total tile count by the number of tiles in a box and round up. Enter the tiles per box in the calculator's optional field and it shows the box count next to the tile count, or switch Sold by to Box and enter the square footage each box covers.
How much extra tile should I buy for waste?
For a standard straight lay, add about 10% for cuts, breakage and future repairs. For diagonal or herringbone layouts, or rooms with lots of cuts, add about 15%. Tap “+ Add waste calc” in the project total to add a percentage buffer.
Does this tile calculator work for walls and backsplashes?
Yes. The math is the same for any flat area — enter the height and width of a wall or backsplash instead of a floor's length and width. Add each wall and floor to the project total to get a single tile count and cost for the whole job.