Use our free tile calculator to find out exactly how many tiles you need for any floor or wall. Enter your room size and tile dimensions, set a wastage allowance, and get an instant result — no sign-up required.
Tile Calculator
Room Dimensions
Tile Size
How to Use the Tile Calculator
- Enter your room length and width (switch to Imperial if you work in feet).
- Choose a common tile size from the preset list, or type in custom dimensions.
- Set the grout joint width — 3mm is standard for floor tiles, 2mm for wall tiles.
- Enter your wastage percentage. 10% is recommended for straight laying; use 15–20% for diagonal patterns.
- Optionally enter the number of tiles per box to get a box count.
- Click Calculate Tiles to see your results instantly.
How Much Wastage Should I Allow?
Tile wastage accounts for cuts, breakages, and off-cuts that cannot be reused. As a general rule:
- 10% — Standard straight lay on a regular rectangular room.
- 15% — Room with multiple alcoves, obstacles or irregular shape.
- 20%+ — Diagonal (45°) laying pattern, which produces significantly more cut waste.
It is always better to buy slightly more than you need. Tile batches vary in shade between production runs (known as the dye lot), so buying extra upfront ensures you can replace broken tiles with a perfect match in the future.
Common Tile Sizes
The tile market has shifted strongly towards larger format tiles in recent years. Here are the most popular sizes you will find in UK builders merchants and tile shops:
| Tile Size | Common Use | Approx. Tiles per m² |
|---|---|---|
| 600 × 600 mm | Floors, large open areas | 2.8 |
| 600 × 300 mm | Floors and walls | 5.6 |
| 1200 × 600 mm | Large open plan floors | 1.4 |
| 450 × 450 mm | Bathroom and kitchen floors | 4.9 |
| 300 × 300 mm | Walls, shower enclosures | 11.1 |
| 800 × 400 mm | Floors and feature walls | 3.1 |
Tile Calculator — Frequently Asked Questions
How many 600×600 tiles do I need for 10 m²?
A 600×600mm tile covers 0.36 m² (including a 3mm grout joint, the effective area is slightly larger). For a 10 m² floor you would need approximately 28 tiles before wastage — add 10% to get 31 tiles. Our calculator handles this instantly once you enter your dimensions.
Should I add extra wastage for diagonal tile laying?
Yes. Laying tiles at 45° to the wall increases cut waste considerably, particularly along the room edges where triangular cuts are required. Increase your wastage allowance to at least 15–20% for a diagonal pattern.
What is a grout joint and why does it matter?
A grout joint is the small gap left between tiles that is later filled with grout. It allows for minor variations in tile size and thermal movement of the floor. A standard joint is 2–3mm for rectified tiles and 3–5mm for non-rectified tiles. Including the grout joint in your tile size calculation gives a more accurate tile count, which is why this calculator factors it in by default.
How do I calculate how many boxes of tiles I need?
Enter the number of tiles per box in the optional field and our calculator will automatically divide your total tile count (including wastage) by the box size, rounding up to the nearest whole box. The tiles per box figure is usually printed on the box label or available on the tile retailer’s website.
