Tile Calculator
Enter your area and tile size to find out exactly how many tiles — and how many boxes — to buy for your project.
How to use the tile calculator
- Choose your unit system (metric or imperial).
- Enter the length and width of the area you're tiling.
- Enter the size of a single tile and how many tiles come in a box.
- Adjust the waste allowance if your layout has a lot of cuts (diagonal, herringbone, etc.).
- Read off the tiles and boxes needed — the result updates as you type.
How it works
The calculator first finds the area to be tiled: Area = Length × Width. It then divides that by the area of a single tile to get a base tile count, and adds your waste percentage (10% by default, to cover cuts, breakages, and future repairs) to get the total tiles needed: Total tiles = (Area ÷ Tile area) × (1 + Waste%). Finally it divides by the number of tiles per box and rounds up, since you can only buy whole boxes.
Examples
| Input | Result |
|---|---|
| 12 m² room, 30×30 cm tiles, 10 per box, 10% waste | ≈ 147 tiles → 15 boxes |
| 120 ft² room, 12×12 in tiles, 8 per box, 10% waste | ≈ 132 tiles → 17 boxes |
Frequently asked questions
How much extra tile should I buy for waste?
A 10% allowance covers most straight-lay jobs. For diagonal, herringbone, or rooms with lots of corners and cuts, increase it to 15–20%.
Should I include the area of doorways in my measurement?
Yes, measure the full floor or wall area including doorways and alcoves — it's easier to subtract obvious no-tile zones (like a fixed cabinet footprint) than to add them back later.
How do I calculate tiles for a wall with a window?
Calculate the full wall area first, then subtract the window or door area, and apply the waste percentage to the remaining tileable area.
Does grout line width change how many tiles I need?
Grout lines have a negligible effect on quantity for most tile sizes. For very large-format tiles or wide grout joints, add an extra 2–3% to your waste allowance.
Why does the calculator round up to full boxes?
Retailers sell tile by the box, not individually, so we round the total up to the next whole box to make sure you don't run short mid-project.
Can I use this for both floor and wall tiles?
Yes — the math is identical. Just measure the surface you're covering and enter the correct tile dimensions.