Tile Calculator
Tile Calculator
Estimate the tiles you need for floors, walls, backsplashes and other rectangular surfaces — including cutting waste and tile boxes.
Enter the coverage printed on the tile packaging. This is often more reliable than calculating box coverage yourself.
Optional: subtract large areas that will definitely not receive tile.
Buying tile is one of those jobs where a small measuring mistake can turn into an expensive extra trip to the store.
Our tile calculator helps you work out how many tiles you need from the dimensions of the area and the size of your tile. You can also account for cutting waste and, when you know the coverage printed on the box, estimate how many boxes to purchase.
It works for floors, walls, bathrooms, kitchens, backsplashes, shower areas, and other rectangular surfaces.
The useful part isn’t just getting a number. It’s seeing how that number changes when you use a different tile size or allow for more cutting waste.
What the tile calculator can help you find
- Total area to cover
- Tile area
- Number of tiles required
- Extra tiles for waste
- Total tiles to order
- Estimated boxes needed
- Tile coverage in square feet
- Tile quantity for floors and walls
- Tile requirements for different tile sizes
Tip: Before ordering, check the manufacturer’s box coverage and keep some spare tiles from the same batch for future repairs.
How Many Tiles Do I Need?
The basic calculation is surprisingly simple:
Tiles needed = Area to cover ÷ Area of one tile
Then add an allowance for cuts and breakage.
For example, suppose you have a 10 ft × 12 ft room.
The room area is:
10 × 12 = 120 square feet
If you’re using 12 × 12 inch tiles, each tile covers:
12 × 12 ÷ 144 = 1 square foot
So the basic requirement is:
120 ÷ 1 = 120 tiles
With a 10% waste allowance:
120 × 1.10 = 132 tiles
You would therefore plan for approximately 132 tiles, before checking how the product is packaged.
The calculator does these conversions for you so you don’t have to switch between feet and inches manually.
Tile Quantity Is Not the Same as Floor Area
This is an easy mistake to make.
If a room is 150 square feet, that doesn’t automatically mean you need 150 tiles.
The number of tiles depends on tile dimensions.
For example:
| Tile size | Approx. coverage per tile |
|---|---|
| 6 × 6 in | 0.25 sq ft |
| 8 × 8 in | 0.44 sq ft |
| 12 × 12 in | 1 sq ft |
| 12 × 24 in | 2 sq ft |
| 18 × 18 in | 2.25 sq ft |
| 24 × 24 in | 4 sq ft |
So the same 100-square-foot room could require hundreds of small tiles or only a few dozen large tiles.
That’s why a useful tile square footage calculator needs both the surface dimensions and the tile dimensions.
Don't Ignore Tile Waste
The mathematical minimum isn’t necessarily the quantity you should buy.
Tiles need to be cut around walls, corners, doorways, cabinets, drains, pipes and other obstacles. Some offcuts can be reused, while others are too small to be useful. Tiles can also crack during cutting or installation.
A common starting point for a straightforward layout is around 10% extra, while diagonal and more complicated patterns can require a larger allowance. Current tile-calculator references commonly use roughly 10% for straight layouts and 15% or more for more cut-intensive patterns.
A practical starting guide
| Installation situation | Example waste allowance |
|---|---|
| Simple rectangular room, straight layout | 10% |
| Offset / brick layout | 10–15% |
| Diagonal layout | 15%+ |
| Herringbone or chevron | 15–20%+ |
| Many corners, niches or obstacles | Consider increasing allowance |
| Small room with large tiles | Consider increasing allowance |
These are planning allowances, not guarantees. The right amount depends on the actual room, tile, layout and installation method.
How to Calculate Tile for a Floor
For a simple rectangular floor:
Step 1 — Measure the room
Measure the length and width of the floor.
For example:
12 ft × 15 ft
Step 2 — Calculate the floor area
12 × 15 = 180 sq ft
Step 3 — Measure the tile
Suppose the tile is:
12 × 24 inches
Its area is:
12 × 24 ÷ 144 = 2 sq ft
Step 4 — Divide the floor area by tile coverage
180 ÷ 2 = 90 tiles
Step 5 — Add your waste allowance
At 10%:
90 × 1.10 = 99 tiles
So you’d plan on approximately 99 tiles, then convert that quantity into whole boxes using the coverage or tile count shown on the manufacturer’s packaging.
How to Calculate Wall Tile
The same basic idea works for walls.
For a rectangular wall:
Wall area = wall length × wall height
For example:
10 ft × 8 ft = 80 sq ft
If you’re tiling several walls, calculate each wall separately and add the areas together.
Don’t forget to subtract large areas that will definitely not be tiled, such as a large opening, if appropriate.
For bathrooms and showers, however, the shape can become much more complicated because of doors, niches, benches, windows, plumbing penetrations and other interruptions.
In those cases, breaking the project into smaller rectangles can make the estimate easier to check.