Bathroom Tile Calculator
Work out exactly how many tiles and boxes you need for your bathroom floor or walls, with a built-in wastage allowance for cuts and breakages.
Calculate Tile Quantity
Enter the size of the area you’re tiling, the size of your chosen tile, and a wastage allowance. The calculator instantly works out the total tiles, area, and boxes required.
Tile Quantity Calculator
Get an instant tile count with a safe cutting allowance.
Understanding Tile Quantities
Key concepts for accurate ordering and less waste
Measure Each Surface
Measure the length and height (or width) of every wall or floor section separately, then run the calculator for each one before totalling the results.
Why Wastage Matters
Cutting tiles around corners, pipes, and fittings always creates offcuts. A 10–15% allowance covers this without leaving you short mid-job.
Rounding Up to Boxes
Tiles are sold by the box, and boxes can’t be split. Always round the final tile count up to the next full box, not down.
Pattern & Layout
Diagonal, herringbone, and brick-bond layouts generate more offcuts than a simple straight lay, so increase your wastage allowance accordingly.
Tile Sizes & Wastage Guide
Common bathroom tile sizes, their coverage per tile, and a recommended wastage allowance for a straightforward, straight-lay installation.
| Tile Size | Coverage per Tile | Typical Use | Suggested Wastage |
|---|---|---|---|
| 10 × 10 cm — 0.01 m² | Mosaic accents, splashbacks | 15% | |
| 15 × 15 cm — 0.0225 m² | Walls, shower surrounds | 12% | |
| 20 × 20 cm — 0.04 m² | Walls and floors | 10% | |
| 30 × 30 cm — 0.09 m² | Floors, general bathroom use | 10% | |
| 30 × 60 cm — 0.18 m² | Walls and floors | 10% | |
| 60 × 60 cm — 0.36 m² | Large-format floors | 12% | |
| 60 × 120 cm — 0.72 m² | Feature walls, large floors | 15% | |
| 100 × 100 cm — 1.00 m² | Statement floors and walls | 18% |
Tile Calculator FAQ
Answers to the most frequently asked questions about measuring and buying bathroom tiles.
Multiply the length and width of the area in metres to find the total square metreage, then divide by the coverage of a single tile. Add a wastage allowance of around 10% for straight lays or 15% for diagonal lays and cuts, then round up to the nearest full box.
A standard allowance is 10% extra for a simple, square room with a straight tile layout. For rooms with alcoves, diagonal patterns, or large-format tiles, increase the allowance to 15–20% to cover cuts and breakages.
Yes. Floor tiles and wall tiles are usually different sizes and finishes, so it’s best to calculate the floor area and each wall area separately, then run the calculator once for each surface before adding the totals together.
For large openings such as a shower screen, bath panel, or a door that reduces wall area significantly, it’s worth subtracting their area from the total. For smaller fixtures like a sink or toilet, most installers skip subtracting since the wastage allowance typically covers the extra cuts.
The maths is identical — area divided by tile coverage, plus wastage — but wall tiles are usually thinner and lighter than floor tiles, and floor tiles need to be slip-rated. Always check a tile is suitable for its intended surface before ordering.