How many wall tiles do I need?
Find the tiled area, add spare for cuts and divide by the area of one tile. Here is the rule, a worked example with subway tiles and a free calculator.
How do I calculate how many tiles I need?
Work out the area you will tile by multiplying its width by its height, then subtract windows, doors and cupboards inside it. Add 10% for cuts and breakage. Divide that total by the area of one tile, so a 15 × 7.5 cm or 6 × 3 inch subway tile covers 112.5 cm² or 18 in².
Worked example: a subway tile backsplash
- Backsplash 3 m × 0.6 m = 1.8 m² (10 ft × 2 ft = 20 ft²).
- Add 10% spare: 1.98 m² (22 ft²).
- One 15 × 7.5 cm tile is 0.01125 m², so 1.98 ÷ 0.01125 = 176 tiles. In inches, a 3 × 6 tile is 0.125 ft², so 22 ÷ 0.125 = 176 tiles.
Do I need to count the grout lines?
No. Grout joints are only a few millimetres wide, so ignoring them means your count comes out very slightly high, which acts as a small extra spare. If you buy tiles by the box, divide the tiled area plus spare by the area printed on the box instead, and round up to whole boxes.
How high should wall tiles go?
Kitchen backsplashes usually run from the worktop to the underside of the wall cabinets. Bathrooms are often tiled to about half height, around 1.2 m or 4 ft, with full height inside showers. Roomveil lets you switch between half and whole wall and recounts the tiles straight away.
Try the look on your wall
In Roomveil, pick subway, square, large or slab tiles, a colour and a grout colour, and see them on your wall with the shadows from your photo. The tile count and spare update as you change the choices.
These are common rules of thumb and code minimums, given for planning. Always check the product label, the maker's instructions and your local building code before you buy or build.