Tile Calculator
Enter the area to cover, pick a tile size and waste factor to get tiles and boxes required.
Quick answer
With the default inputs: Area to tile 30 m² · Tile size 800 × 800 mm · Tiles per box 3 pcs etc.Tiles required 51 pcs
Edit the inputs below to recalculate.Inputs
Result
Tiles required
51pcs
| Area per tile | 0.6400m² |
| Tiles per m² | 1.56pcs |
| Net tiles | 47pcs |
| With waste | 51pcs |
| Boxes | 17boxes |
| Coverage per box | 1.92m² |
| Tiles purchased | 51pcs |
| Purchased area | 32.64m² |
Boxes are rounded up to whole boxes. Keep one spare — later batches can differ in shade.
Reverse: known result, work out one input
Enter a target result; the other inputs stay fixed and this one is worked out.
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 |
How to work it out
- Establish the net tiling area (do not deduct for drains, do deduct for columns), then the area of one tile.
- Divide one by the other for a theoretical count — that is only a starting point; the layout governs the real number.
- Do the setting-out: divide room length and width by tile length and width, round each up, and multiply. That gives the whole tiles actually needed.
- Add waste by pattern: 5% for stacked straight lay, 10-12% for diagonal, 15-18% for herringbone.
- Round up to whole boxes and keep a further 3-5% as spares — cut-offs are not spares.
Where it goes wrong
- Dividing area only, ignoring setting-out — a 3.3 m wide room in 800 mm tiles is 4.125 tiles across on paper but needs five columns in practice; the extra 0.7 m is all cut from full tiles, costing far more than the waste allowance.
- Treating waste as spares — waste is what gets cut off, spares are what you keep for later repairs. Run short by 20 tiles at handover and the batch is gone.
- Measuring bathrooms to the structural net size, forgetting whether floor tiles run under or up to the wall tiles — that changes the boundary by one tile thickness.
- Combining several areas into one order — the same model from a different batch can shade differently; order by area and record the batch.
Material and cost
800×800 glazed porcelain 60-120 CNY per tile (95-190 CNY/m²); 600×600 30-70. Labour 35-55 CNY/m², +20% for diagonal, +40% for herringbone. Adhesive or mortar 15-30 CNY/m² on top.
On site
- Check shade and batch codes before opening. Lay one room from a single opening so any variation is invisible.
- Porcelain with below 0.5% absorption must go on walls with cement-based adhesive plus a bonding slurry; sand-cement mortar will not hold it and it debonds within a couple of years.
- Hollow spots are the acceptance metric: no single tile over 5% hollow and no more than 5% of tiles in a room. A tap test tells you more than a visual inspection.
Basis
- GB 50209-2010 Code for acceptance of building floor construction, Chapter 6 (tile surfacing)
- GB 50210-2018 Code for acceptance of building decoration, Chapter 8 (wall tiling)
- GB/T 4100-2015 Ceramic tiles
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.
Cite this page
Use this format in reports, method statements or coursework. The link is permanent.
Building Calculator. Tile Calculator. 2026-10-25. https://jianzhujisuan.com/en/tile-count
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.