Bathroom Tile Calculator
Estimate how many tiles you need to tile a bathroom floor and walls. Enter the floor dimensions, the wall height and perimeter, your tile size and a wastage allowance, and the calculator works out the floor area, wall area, total area and the number of tiles to buy.
Formula
FloorArea = L×W; WallArea = Perimeter×Height; Tiles = ⌈TotalArea/TileSize² × (1+Wastage%)⌉
- Floor area = length × width; wall area = perimeter × wall height.
- Each square tile covers its side length squared (e.g. a 0.3 m tile covers 0.09 m²).
- Tiles needed = total area ÷ tile area, increased by the wastage allowance and rounded up.
- A 10–15% wastage allowance is standard to cover cuts, breakages and future repairs; use more for diagonal layouts or busy patterns.
- This estimate doesn't subtract doors or fixtures — the extra tiles act as a useful buffer.
3 × 2.5 m floor, 2.4 m walls, 11 m perimeter, 0.3 m tiles, 15% waste
Inputs
- Floor Length: 3 m
- Floor Width: 2.5 m
- Wall Height: 2.4 m
- Wall Perimeter: 11 m
- Tile Size (square): 0.3 m
- Wastage Allowance: 15 %
Floor = 7.5 m², walls = 26.4 m², total = 33.9 m². Each tile = 0.09 m², so 33.9 ÷ 0.09 ≈ 377 tiles, then × 1.15 for wastage ≈ 433 tiles.
Frequently asked questions
How many tiles do I need for my bathroom?
Add the floor area and wall area, divide by the area of one tile, then add a wastage allowance. This calculator does it for you and rounds up to whole tiles.
How much wastage should I allow?
Around 10–15% for a standard straight layout. Allow more — up to 20% — for diagonal patterns, lots of cuts, or rooms with awkward shapes.
Should I subtract doors and windows?
This estimate doesn't, which leaves a buffer. If your openings are large you can subtract their area from the wall area, but keep some spare tiles for repairs.
Why keep extra tiles after the job?
Tile batches vary in colour and may be discontinued. Keeping a few spares means you can replace a cracked tile later with an exact match.