How to use the tile calculator
- Enter the floor or wall area. For walls, use the wall's width and height; subtract windows by calculating them separately.
- Enter the tile size (as it says on the box, not including grout).
- Adjust the waste allowance for your layout, and enter the number of tiles per box.
The formula
tiles = area × (1 + waste %) ÷ area of one tile (rounded up)
boxes = tiles ÷ tiles per box (rounded up)
Tiles per square metre
| Tile size | Tiles per m² (no waste) |
|---|---|
| 30 × 30 cm | 11.11 |
| 30 × 60 cm | 5.56 |
| 60 × 60 cm | 2.78 |
| 10 × 10 cm | 100 |
Worked examples
Metric: a 3 m × 2 m floor with 60 × 30 cm tiles: 6 m² plus 10% = 6.6 m² ÷ 0.18 m² = 37 tiles, or 5 boxes of 8.
Imperial: an 8 × 5 ft bathroom floor with 12 × 24 in tiles: 40 sq ft plus 10% = 44 sq ft ÷ 2 sq ft = 22 tiles, or 3 boxes of 8.
Before you buy
- Check the batch. Tiles from different production batches can differ slightly in colour — buy all you need at once.
- Keep spares. A few leftover tiles make future repairs invisible.
- Plan the layout to avoid thin slivers at the edges; it can change how many cuts you make.
- Adhesive and grout are separate purchases — their coverage is printed on the bag.
Common mistakes to avoid
- Using the nominal size. Some tiles are sold by a rounded size; use the actual size on the box.
- Too little waste for patterns. Diagonal and herringbone layouts create more offcuts.
- Buying more later. A second order may come from a different batch with a slightly different shade.
Measuring an awkward shape? See how to measure an irregular area.
Frequently asked questions
How many 30 × 30 cm tiles are in a square metre?
About 11.1 — one square metre divided by 0.09 m² per tile. For 60 × 60 cm tiles it is about 2.78. Always round up and add your waste allowance.
How many 12 × 12 inch tiles do I need per square foot?
Exactly one, because a 12 × 12 in tile is one square foot. A 12 × 24 in tile covers two square feet.
How much extra tile should I buy?
Cuts at walls, corners and around fittings always waste some tiles, and a few may break. The calculator adds 10% by default. Increase it for diagonal layouts, patterned layouts, many cuts, or large tiles in a small room — and keep a few spare tiles for future repairs.
Does the calculator allow for grout lines?
No — it treats tiles as if they touch. Grout joints make each tile cover slightly more area, so ignoring them gives a slightly higher (safer) tile count.
Last updated 10 November 2026. Found a mistake? Tell us.