Use this free tile calculator to work out how many tiles and boxes you need for a floor, wall or backsplash, including grout lines and extra tiles for cuts.
Home projects · feet or metersTile Calculator
Also, grout, adhesive and trim pieces are not included.
Our free tile calculator tells you exactly how many tiles to buy, so you finish the job without a second trip to the store. To begin with, enter the size of the floor or wall. Then choose your tile size and grout joint. After that, the calculator adds extra tiles for cuts and shows the number of tiles, boxes and the cost.
How the Tile Calculator Works
In practice, each tile covers its own face plus half of the grout line around it. Therefore, the calculator adds the joint width to the tile size before dividing.
Firstly, it multiplies the length by the width of the space.
Then it adds the grout joint to the tile’s length and width.
Finally, it divides the area by one tile and adds your waste allowance.
The formula
Tiles = Area ÷ ((Tile length + joint) × (Tile width + joint)) × (1 + waste %)
Tile Calculator Examples
For example, here are three common jobs with 10% extra, so you can see how tile size changes the count.
To illustrate, this floor uses 12 × 12 inch tiles with 1/8 inch joints.
- Firstly: area 40 sq ft
- Then: tiles before extra 39.18
- Also: boxes of 10 5
Similarly, this kitchen uses 12 × 24 inch tiles at $3.50 per square foot.
- Firstly: area 120 sq ft
- Then: tiles before extra 59.07
- Also: cost $455.00
In contrast, this backsplash uses small 3 × 6 inch subway tiles.
- Firstly: area 15 sq ft
- Then: tiles before extra 116.34
- Also: joint 1/16 in
Tile Calculator: Tiles per 100 Square Feet
Specifically, this table assumes 1/8 inch grout joints. In addition, the last column includes 10% extra for cuts.
| Tile size | Sq ft per tile | Tiles (no extra) | Tiles to buy |
|---|---|---|---|
| 4 × 4 in | 0.11 | 846.3 | 931 |
| 3 × 6 in | 0.12 | 752.3 | 828 |
| 6 × 6 in | 0.25 | 383.8 | 423 |
| 12 × 12 in | 1.00 | 98.0 | 108 |
| 6 × 24 in | 1.00 | 97.5 | 108 |
| 12 × 24 in | 2.00 | 49.2 | 55 |
| 18 × 18 in | 2.25 | 43.8 | 49 |
| 24 × 24 in | 4.00 | 24.7 | 28 |
| 8 × 48 in | 2.67 | 36.8 | 41 |
How Much Extra Tile to Buy
- Straight layout: for instance, add 10% for cuts and breakage.
- Diagonal or herringbone: similarly, add 15% or more, since edges need many angled cuts.
- Small or odd-shaped rooms: also, add up to 20%, because a bigger share of tiles gets cut.
Choosing a Grout Joint Size
For instance, rectified porcelain tiles can use joints as thin as 1/16 inch. However, most floor tiles use 1/8 to 3/16 inch joints, while handmade or rustic tiles need 1/4 inch or more. In general, follow the tile maker’s advice and the guidance from the Tile Council of North America.
Floor Tile vs Wall Tile
Floor tiles must handle foot traffic, so look for a slip-resistant porcelain rated for floors. On the other hand, wall tiles can be thinner and lighter, such as glossy ceramic subway tiles. As a result, never use a wall-only tile on a floor.
How to Use This Calculator
- To begin with, choose feet or meters, and measure by size or total area.
- Then enter the area and your tile size.
- After that, pick the grout joint and the extra percentage.
- Finally, add tiles per box and price if you like, then press Calculate tiles.
More Home Project Tools
These tools also help with home jobs. Besides, you can browse all our construction calculators.
Tile Calculator FAQs
How many tiles do I need for 100 square feet?
For example, with 12 × 12 inch tiles and 1/8 inch grout lines, you need about 98 tiles. Then add 10% for cuts, so buy about 108 tiles.
Does the tile calculator include grout lines?
Yes, it adds the grout joint to each tile’s size, so the count matches a real layout. As a result, wider joints need slightly fewer tiles.
How much tile waste should I allow?
Generally, allow 10% for a straight layout. However, use 15% for diagonal or herringbone patterns, and up to 20% for small rooms with many cuts.
How many tiles are in a box?
Above all, it depends on the tile size. For instance, a box of 12 × 12 tiles often holds 10 to 15 tiles, while large 24 × 24 tiles may come 2 to 4 per box.
Should I keep spare tiles?
Yes, keep at least a few spares from the same batch. Otherwise, a later repair may not match, because colors vary between production runs.
How do I measure an L-shaped room?
First of all, split the room into two rectangles and multiply the length by the width of each. Then add the two areas, and choose Total area in the calculator.
Disclaimer: Overall, this calculator gives an estimate for planning only. Also, layout, pattern and tile size all affect waste, so check with your tile supplier or installer before ordering.