Bathroom Tile Calculator

Calculating bathroom wall tiles

The wall tile area works out to perimeter · height − door/window area. On top of that, budget 10% waste, since you'll cut tiles around fixtures and a few will break. Plenty of homes don't tile all the way to the ceiling. They stop at 1.80 m, just above the shower head, which trims the material bill. Take a 2 × 3 m bathroom with a 2.70 m ceiling: the perimeter of 10 m times 2.70 m gives 27 m² of wall, knock off about 1.6 m² for the door, and 25.4 m² × 1.10 lands you near 28 m². Figure the floor separately. In Brazil, NBR 13818 is the standard that classifies wall tile.

Applications and standards

People reach for this when planning a residential bathroom renovation, pricing out hotel and commercial restrooms, or putting together a quote with a tiler. Inside the shower box you need AC-II adhesive, the water-resistant kind, because that area stays wet. AC-I has no business in a wet zone. Above the box, though, AC-I is fine. Settle on grout color and width (1.5–3 mm) before you buy, and use epoxy grout in the shower zone if you can, since it holds up against mildew far better than cementitious grout.

FAQ

Tile the full height or stop at 1.80 m? Going all the way up looks cleaner and wipes down more easily. Stopping at 1.80 m cuts your tile by roughly 30%, which is why it shows up so often in tighter renovations.

Do I subtract the door area? Yes. A standard door runs about 0.80 × 2.10 m, so around 1.7 m². Take out windows as well. Leave the small fixtures like the toilet and sink in the count, because you're still cutting tile around them.

Same tile for wall and floor? Floors have to handle PEI 3+ and offer slip resistance, while walls carry no PEI requirement at all. A lot of product lines do sell coordinated wall and floor sets if you want them to match.