Enter the size of the area, the size of your tiles, the grout gap and an allowance for waste. The calculator shows the number of tiles and boxes to buy.
Results are estimates for planning. Check the figures before you make a financial or health decision.
How the Tile calculator works
The calculator divides the area by the space each tile takes up, grout included, and then adds waste.
- Area = length × width. You can enter metres or feet.
- Tile footprint = (tile length + grout gap) × (tile width + grout gap).
- Tiles without waste = area ÷ tile footprint, rounded up.
- Tiles needed = that number × (1 + waste %), rounded up.
- Boxes = tiles needed ÷ tiles per box, rounded up.
The waste allowance starts at 10%, which covers cuts and breakages on a straightforward layout. The tool also shows the area in square metres and square feet, and how many tiles are in the boxes you buy.
It assumes one simple rectangle and the same tile throughout. It does not handle several rooms at once, borders, or cutting around fixed items. Diagonal and herringbone layouts need more tiles, so raise the allowance to 15% or more.
Worked example
Using the default values in the calculator above:
| Input | Value |
|---|---|
| Room measurements in | Metres |
| Area length | 4 |
| Area width | 3 |
| Tile length | 60 cm |
| Tile width | 30 cm |
| Grout gap | 3 mm |
| Extra for cuts and breakages | 10 % |
| Tiles per box | 6 |
Tiles needed: 73 tiles
| Area to tile | 12 m² (129.2 sq ft) |
|---|---|
| Tiles without waste | 66 |
| Boxes to buy | 13 |
| Tiles in those boxes | 78 |
Tips and common mistakes
For an L-shaped or complicated room, split it into rectangles, run each and add the totals. Enter the tile size in centimetres and the gap in millimetres, as labelled.
Buy all your tiles together, since colours and sizes can vary between batches, and keep a few spares for future repairs. Check the pack size, as some tiles are sold by the square metre rather than by the box. Large format tiles and patterned tiles can produce more waste, so consider a higher allowance. For other surfaces, see the Area and square footage calculator.
Frequently asked questions
How much extra should I buy for waste?
Ten per cent is a common allowance for simple layouts. Use 15% or more for diagonal, herringbone or patterned layouts.
Does the grout gap matter?
Yes. It is added to each tile’s size when working out how many fit, so wider gaps mean fewer tiles over the same area.
Can I enter feet instead of metres?
Yes. Switch the room measurements to feet. Tile size is still entered in centimetres and the gap in millimetres.