Tile Calculator
Enter the area to cover, pick a tile size and waste factor to get tiles and boxes required.
Inputs
Result
Formula
| Tile area | A = length × width (convert mm to m) |
| Tiles per m² | N = 1 ÷ A |
| Net tiles | N_net = area × N |
| Actual tiles | N_actual = N_net × (1 + waste %), rounded up |
| Boxes | boxes = ceil(N_actual ÷ tiles per box) |
30 m² with 800×800 tiles: 0.64 m² each, 1.56 per m², 47 net, 51 with 8% waste, and 17 boxes at 3 per box.
Tiles per square metre by size
| Size | Area per tile (m²) | Tiles per m² | Typical per box | Typical use |
|---|---|---|---|---|
| 300 × 300 | 0.09 | 11.11 | 11 | Bathroom floors |
| 300 × 600 | 0.18 | 5.56 | 8 | Kitchen walls |
| 400 × 400 | 0.16 | 6.25 | 6 | Balconies, small rooms |
| 600 × 600 | 0.36 | 2.78 | 4 | Living rooms, bedrooms |
| 800 × 800 | 0.64 | 1.56 | 3 | Large living areas |
| 600 × 1200 | 0.72 | 1.39 | 2 | Large-format wall panels |
| 750 × 1500 | 1.125 | 0.89 | 2 | Large-format continuous floors |
FAQ
What waste factor should I use?
5% for a straight lay in a square room, 8% for a typical room with corners and cut tiles, 12% for diagonal or herringbone patterns, and 15% for small tiles or complicated layouts with many pipes and angles. Waste comes mostly from edge cuts.
Why keep a spare box?
Tiles are fired in batches and colour varies between them. If a few break later, a replacement order months on will almost certainly be a different batch and visibly different in colour. Keep one unopened box, which many suppliers will take back.
Can wall tiles and floor tiles be swapped?
Not freely. Floor tiles have low absorption (≤0.5%) and high abrasion resistance, so they can go on walls but are heavy and need tile adhesive plus a keyed substrate. Wall tiles absorb around 10% and are weak enough to crack underfoot. Bathroom floors need slip-resistant tiles with a friction coefficient of at least 0.5.
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Results are estimating aids only and are not a design basis. Construction and final accounts must follow the drawings, the applicable standards and an approved method statement. Anything affecting structural safety, shoring or falsework must be checked by a suitably qualified engineer.