Tile Calculator
Work out how many tiles and boxes you need for a floor or wall, allowing for grout gaps and extra for cuts and breakages.
New: please check your results.
- Tiles to buy
- 72 tiles
- Boxes
- 7 boxes
- Area to tile
- 6 m²
- Tiles per m²
- 10.89
What it does
Find how many tiles you need to cover a floor or wall. Enter the area's size, the tile size and the grout gap, add extra for cuts and breakages, and see the number of tiles and boxes to buy.
How to use it
- Area length
The length of the floor or wall to tile. For an L-shaped room, split it into rectangles and add the tiles together.
- Area width (or height)
The width of the floor, or the height of the wall to tile.
- Tile length
The size printed on the box, for example 300 × 300 mm or 600 × 300 mm.
- Tile width
The other side of the tile.
- Grout gap
The space between tiles: often 2 to 3 mm on walls and 3 to 5 mm on floors. Use 0 to ignore it.
- Extra for cuts and breakages
10% is usual for a straight layout. Allow about 15% for diagonal or herringbone patterns, or for lots of cuts.
- Tiles per box
From the box or the product page. Used to work out how many boxes to buy.
Common uses
- Buying floor tiles for a kitchen, bathroom or hallway.
- Tiling a splashback or shower wall.
- Working out paint for the rest of the room. Try the Paint Calculator
- Working out the area of an awkward shape. Try the Area Calculator
The formula
Area = length × widthTiles = area ÷ ((tile length + gap) × (tile width + gap))To buy = tiles × (1 + extra ÷ 100), rounded upBoxes = tiles to buy ÷ tiles per box, rounded upWhere:
- gap
- the grout joint, which each tile shares with its neighbours
Measure the area and tiles in any units: millimetres, metres, inches and feet can be mixed.
Worked example
A 3 m by 2 m floor with 300 mm by 300 mm tiles and a 3 mm gap:
- Area: 3 m × 2 m = 6 m²
- Each tile with grout covers 0.0918 m², so 65.35 tiles fill it
- With 10% extra: 72 tiles, which is 7 boxes of 11
Questions people ask
How much extra tile should I buy?
About 10% for a simple straight layout, and 15% or more for diagonal or herringbone patterns, small rooms with lots of cuts, or natural stone. Keep a few spare tiles for future repairs, as batches can vary in shade.
Should I take off the area of a bath or kitchen units?
Yes. Work out the area of anything you won't tile under and subtract it, or split the space into rectangles and only count the parts you'll tile.
Why do grout gaps matter?
Each gap adds a little to every tile's footprint. With small tiles and wide joints this can reduce the number of tiles you need by several percent.
Last checked 26 October 2026