🪟 Construction
Tile Calculator
Enter the room dimensions and the tile size, then press Calculate to get the tile count including a wastage allowance.
About the Tile Calculator
Tiles are bought by count, not by area, so the calculation is area divided by area per tile, then rounded up. A 60 × 60 cm tile covers 0.36 m², so a 12 m² floor needs 34 tiles before waste.
Add 10% for a simple rectangular room and 15% for diagonal layouts, herringbone or rooms with many cuts. Keep a spare box: dye lots change, and a chipped tile two years later is impossible to match.
How the calculation works
- Tiles = ceiling(room area × (1 + waste) ÷ tile area)
- Tile area (m²) = length (m) × width (m)
- Add 10% standard, 15% for diagonal or complex layouts
Reference values
| Room | Tile | Tiles needed |
|---|---|---|
| 3 × 3 m | 60 × 60 cm | 28 |
| 4 × 3 m | 60 × 60 cm | 37 |
| 4 × 3 m | 30 × 30 cm | 147 |
| 5 × 4 m | 60 × 60 cm | 62 |
| 2 × 1.5 m | 30 × 60 cm | 18 |
Worked examples
- A 4 × 3 m floor is 12 m²; with 60 × 60 cm tiles that is 34 tiles, or 38 with 10% waste.
- The same floor in 30 × 30 cm tiles needs 134, so 148 with waste.
- A 2 × 1.5 m bathroom wall in 30 × 60 cm tiles needs 17, so 19.
Why waste varies
A plain grid in a rectangular room wastes about 5%. Diagonal layouts cut more, because every edge tile is a triangle, and a room with a doorway, a window and a soil pipe can waste 15%. Buy the extra box in the same batch: dye lots shift slightly, and a later box can be visibly different.
Common mistakes
- Measuring in feet and entering the number as metres.
- Subtracting a shower tray or bath and then forgetting the tiling above it.
- Ordering by box without checking how many tiles a box contains.
A last check on the Room table: 3 × 3 m 60 × 60 cm sits at the base of the chart, and the rows above it step in the same proportion, so you can scale from that first row instead of reading every line. If a figure you were quoted falls between two rows, it is the Tile side that has been rounded, not the conversion itself.