Calculate how many tiles you need for a floor or wall, account for grout joints and unusable areas, add a cutting and breakage allowance, and estimate the number of boxes to buy.
Tile Quantity Calculator
Area dimensions
Tile dimensions
Enter 0 if you do not want to include grout spacing.
Openings and unusable areas
Use this section for areas where tiles will not be installed, such as floor openings, columns, fixed platforms, or other permanent obstructions.
Packaging
Enter 0 if you only want the tile count.
Optional. Use this if the supplier specifies coverage per box.
How the Tile Calculator Works
The calculator starts with the length and width of the area being tiled. It then subtracts any openings or permanent areas where tiles will not be installed.
The tile dimensions and grout joint are used to estimate the space occupied by each tile in the finished layout. The net area is then divided by this coverage to estimate the tile count.
Finally, the selected waste allowance is added and the result is rounded up to a whole tile.
Basic tile calculation formula
Area = length × width
Net area = total area − unusable area
Tile coverage = (tile length + grout joint) × (tile width + grout joint)
Tiles required = net area ÷ tile coverage
Tiles to order = tiles required × (1 + waste percentage ÷ 100)
Example: 6 m × 4 m Floor With 600 × 600 mm Tiles
Consider a room measuring 6 m × 4 m. You are using 600 × 600 mm tiles, a 3 mm grout joint, and a 10% waste allowance.
| Measurement | Value |
|---|---|
| Floor area | 24.00 m2 |
| Tile size | 600 × 600 mm |
| Grout joint | 3 mm |
| Approximate modular coverage | 0.3636 m2 |
| Tiles before waste | About 66 tiles |
| 10% waste allowance | About 7 tiles |
| Planning quantity | About 73 tiles |
How Much Tile Waste Should You Allow?
Waste depends on the shape of the room, tile pattern, number of corners, tile size, and amount of cutting required.
| Project type | Typical planning allowance |
|---|---|
| Simple rectangular room | 5% to 10% |
| Several corners or obstacles | 10% to 15% |
| Diagonal or complex pattern | 15% or more |
These are planning figures, not universal installation requirements. Tile manufacturers and experienced installers might recommend different allowances for particular products and layouts.
Why Tile Size Matters
Larger tiles cover more area per piece, but they often require more careful layout and cutting around corners, drains, columns, and other obstacles.
Smaller tiles require more individual pieces and more grout joints. They also create more opportunities for small cuts around edges.
The most useful quantity estimate therefore considers both the tile dimensions and the actual layout of the room.
Common Tile Calculation Mistakes
- Calculating the room area but forgetting doors, columns, floor openings, or other unusable areas.
- Using the nominal tile size without checking the manufacturer's actual dimensions.
- Ignoring grout spacing when planning the layout.
- Ordering the exact calculated quantity with no allowance for cuts or breakage.
- Forgetting that tiles are often sold by the box rather than individually.
- Mixing metric and imperial measurements without converting them first.
- Assuming every tile can be reused after it has been cut.
Tile Calculator FAQs
How many tiles do I need for a floor?
Divide the net floor area by the coverage of one tile, then add an allowance for cutting and breakage. Enter the room and tile dimensions above for a quick estimate.
Should I include grout spacing when calculating tiles?
Including the grout joint provides a layout-based estimate because each tile occupies its own face area plus the spacing around it. For ordering purposes, also consider the actual tile dimensions and manufacturer's installation guidance.
How much extra tile should I buy?
A straightforward rectangular room often uses around 5% to 10% extra for cuts and breakage. More complicated patterns, rooms with many corners, and diagonal layouts often require a larger allowance.
How do I calculate how many boxes of tiles I need?
Divide the required tile quantity by the number of tiles in each box and round up to a whole box. If the manufacturer provides coverage per box instead, divide the required area by the box coverage and round up.
Does tile size affect the amount of waste?
Yes. Tile size affects how pieces fit around edges, corners, openings, and other obstacles. Large-format tiles often require careful layout because cuts can be more difficult to position and handle.
Can I use this calculator for wall tiles?
Yes. Use the wall length and height as the area dimensions, then enter the tile dimensions and subtract openings or areas where tiles will not be installed.