Tile and flooring calculator
Tiles and boxes for a floor or wall, with joints and wastage.
How it is calculated
Tiles = area ÷ ((tile length + joint) × (tile width + joint)), plus wastage, rounded up. Boxes = tiles ÷ tiles per box, rounded up.
How to use the Tile Calculator
Find how many floor or wall tiles, and how many boxes, you need for a room, allowing for grout joints and cutting waste.
- Enter the room length and width, or the area if you already know it.
- Deduct any area that will not be tiled, such as built-in units.
- Enter the tile size, the joint width and the wastage.
- Enter the tiles per box to get the number of boxes to buy.
Worked example
A 5 m × 4 m room is 20 m². With 600 × 600 mm tiles and 3 mm joints you need 56 tiles, or 61 with 10% wastage, which is 16 boxes of 4. You buy about 21.96 m² of tile.
Good to know
- Use 10% wastage for straight layouts and 15% or more for diagonal or herringbone patterns.
- Large-format tiles waste more at the edges of small rooms, so round up.
- Keep a few spare tiles from the same batch for future repairs.
Questions
How much wastage should I add?
About 5–10% for straight laying and 10–15% for diagonal or complex layouts.
Is anything I enter saved or sent?
No. The calculation runs in your browser. Nothing you type is sent anywhere. You can copy the result, print it or download it as a CSV.