Tile calculator
Work out the tiles, boxes, grout and adhesive for floors or walls. Add several areas at once for a whole project.
How we calculate
The number of boxes is the net area plus the cutting allowance, divided by the area of one tile and the tiles per box, rounded up.
- Net area Length × width of each area, minus the parts that are not tiled, such as doors, windows or cabinets, added together.
- Tiles Net area × (1 + allowance) ÷ area of one tile, rounded up.
- Boxes Tiles ÷ tiles per box, rounded up. The area you buy can be a little larger than the area you need.
- Grout (A + B) ÷ (A × B) × tile thickness × joint width × 1.6 kg per m². A and B are the tile sides in millimetres, and 1.6 is the grout density. The result is rounded up to 0.5 kg.
- Adhesive 5 kg per m² for tiles with a side of 60 cm or more, and 4 kg per m² for smaller tiles, counted in 25 kg bags.
Cutting allowance by pattern
Brick bond and diagonal patterns leave more cut pieces along the walls, so they need a larger allowance.
| Straight | 5% |
|---|---|
| Brick bond | 7% |
| Diagonal | 12% |
Worked example
A 5 × 4 m room with 60×60 cm tiles, 4 tiles per box, a straight pattern and a 5% allowance:
- Net area
- 20 m²
- Tiles
- 59
- Boxes
- 15
- Grout
- ≈ 2 kg
- Adhesive
- ≈ 4 bags of 25 kg
Results are estimates. Adhesive and grout use depends on the product and how flat the surface is, so follow the instructions on the packaging and confirm with our team before ordering.
Frequently asked questions
How many boxes of tiles for a 5 × 4 m room?
A 5 × 4 m room is 20 m². With 60×60 cm tiles, 4 tiles per box and a 5% cutting allowance, you need 59 tiles, or 15 boxes. The calculator shows this by default. Change the length, width, tile size and laying pattern to suit your room, and add more areas if the project has several rooms.
How much spare tile should I buy?
We use a 5% allowance for a straight pattern, 7% for brick bond and 12% for diagonal, because those patterns leave more cut pieces along the walls. Add more if the room has many corners, columns or curves. You can change the allowance with the slider in the calculator.
How do I work out how much grout I need?
Grout depends on the tile size, the tile thickness and the joint width. The formula is (A + B) ÷ (A × B) × thickness × joint width × 1.6 kg per m², where A and B are the tile sides in millimetres. For 20 m² of 60×60 cm tiles, 9 mm thick, with a 2 mm joint, the result is ≈ 2 kg. Enter the joint width and thickness in the calculator.
How many kilograms of tile adhesive per square metre?
The calculator uses 5 kg per m² for tiles with a side of 60 cm or more and 4 kg per m² for smaller tiles, in 25 kg bags. Actual use depends on the adhesive brand and how flat the surface is, so follow the instructions on the bag. For 20 m² of 60×60 cm tiles, the calculator gives ≈ 4 bags of 25 kg.
How do I calculate tiles for a wall?
Choose Wall as the type of area, then enter the length and height of the wall. Put the area of doors, windows or cabinets that will not be tiled in the Subtract field. You can add several walls and floors as separate areas, and the calculator adds them up into one box count for your project.