Tile Calculator
Tile is sold by the box but laid by the piece, and every cut edge produces an offcut. This tile calculator converts your area into exact tile and box counts for the most popular formats.
Measure the floor or wall area, pick your tile size, set a waste allowance for cuts and breakage, and check how many boxes to buy.
Enter valid values to see the results.
Formula
Tile areas: 30×30 cm = 0.09 m² (1 ft²), 45×45 = 0.20 m² (2.25 ft²), 60×60 = 0.36 m² (4 ft²), 20×120 plank = 0.24 m² (2.67 ft²), 10×20 subway = 0.02 m² (0.22 ft²). Boxes are always rounded up — you cannot buy half a box.
How to measure
- For floors: measure length × width of the room. For walls: measure each wall width × height and add them.
- Deduct only large untiled zones (shower tray, cabinets fixed to the floor); keep small obstacles in — cuts around them consume the waste allowance.
- Check the exact tile size on the box: nominal 30 cm tiles are often 29.5–29.8 cm, which matters over large areas.
Worked example
Practical tips
- Buy all boxes from the same production batch (tone and calibre are printed on the box) to avoid shade differences.
- Keep 2–3 spare tiles after the job for future repairs — collections are discontinued quickly.
- Large-format tiles (60×60 and up) need a very flat subfloor; budget for self-levelling compound if the floor deviates more than 3 mm per metre.
- Diagonal or herringbone layouts need 15% waste instead of the usual 10%.
Waste allowance
Use 5% for simple rectangular rooms with straight layout, 10% for typical rooms with a few cuts, and 15% for diagonal layouts, herringbone or rooms with many corners.
Tiles per unit area by size
| Tile size | Per m² | Per ft² |
|---|---|---|
| 10 × 20 cm (4″×8″) | 50 | 4.5 |
| 30 × 30 cm (12″×12″) | 11.1 | 1 |
| 45 × 45 cm (18″×18″) | 4.9 | 0.44 |
| 60 × 60 cm (24″×24″) | 2.8 | 0.25 |
| 20 × 120 cm (8″×48″) | 4.2 | 0.37 |
Common mistakes
- 1 Ordering by area only and forgetting that boxes contain a fixed number of tiles — always round boxes up.
- 2 Using 5% waste for diagonal layouts, where edge cuts can waste 15% or more.
- 3 Mixing boxes from different batches — shade variation is visible even within the same model.
- 4 Forgetting skirting/threshold tiles and decorative borders in the count.
Frequently asked questions
How many 60×60 tiles do I need for 20 m²?
Each 60×60 cm tile covers 0.36 m², so 20 ÷ 0.36 = 55.6 → 56 tiles. With 10% waste: 62 tiles, i.e. 16 boxes at 4 per box.
How much waste should I add for tiles?
5% for straight layouts in rectangular rooms, 10% as a safe default, and 15% for diagonal, herringbone or complex shapes.
Can I return unused tiles?
Most stores accept unopened boxes within 14–30 days with a receipt. Keep boxes dry and intact, and check the return policy before buying.
Does the calculator include grout and adhesive?
No. As a rule of thumb, tile adhesive is 3–5 kg/m² (10 mm notch trowel) and grout about 0.3–0.5 kg/m² depending on joint width.
What if my tile size is not listed?
Pick the closest size, or divide your area by your tile area directly: tile area = length × width in metres (e.g. 0.25 × 0.4 m = 0.1 m²).