Free and simple, type your room size and tile size and get how many tiles and how many boxes to buy. The answer already includes 10% extra for cuts and breakage, so you do not run short. No sign-up, no email.
Step 1: Measure your room: length and width in feet. For a wall, use the wall's height and width instead.
Step 2: Look at the tile box in the shop: it shows the tile size in inches and how many tiles are in one box. Type both.
Step 3: Press Calculate. You get the exact number of tiles, the number to actually buy with 10% extra, and how many boxes that is.
Step A: Area (sq ft) = Length (ft) × Width (ft). Example: 10 × 10 = 100 sq ft.
Step B: One tile covers: (Tile Length + Gap) × (Tile Width + Gap) ÷ 144. Example for a 12×12 tile with a 1/8 inch gap: 12.125 × 12.125 ÷ 144 = 1.0209 sq ft per tile.
Step C: Tiles exact = Area ÷ Area per tile, rounded UP to whole tiles, tiles are only sold whole, so every step rounds up. Example: 100 ÷ 1.0209 = 97.95, so 98 tiles exact.
Step D: Add the 10% extra to those whole tiles and round up again: 98 × 1.1 = 107.8, so 108 tiles to buy. The same rule for a big 24 × 24 tile in a 180 sq ft room: one tile covers 4.0418 sq ft, 180 ÷ 4.0418 ≈ 44.5 → 45 tiles exact, 45 × 1.1 = 49.5 → 50 tiles to buy.
Rounding rule, the same everywhere on this page: the math always uses the full exact number (like 1.0209, never the short 1.02). Rounding happens only when counting whole tiles and boxes, and always UP, because tiles and boxes are sold whole. Short numbers like 1.02 in text are only for easy reading.
Boxes: Tiles to buy ÷ tiles in one box, rounded up. Example: 108 ÷ 10 tiles per box = 11 boxes.
| Room | Tile Size | Tiles to Buy | Boxes of 10 |
|---|---|---|---|
| Bathroom 5 × 8 ft (40 sq ft) | 12 × 12 in | 44 tiles | 5 boxes |
| Room 10 × 10 ft (100 sq ft) | 12 × 12 in | 108 tiles | 11 boxes |
| Kitchen 10 × 12 ft (120 sq ft) | 12 × 12 in | 130 tiles | 13 boxes |
| Living room 12 × 15 ft (180 sq ft) | 18 × 18 in | 87 tiles | 9 boxes |
| Living room 12 × 15 ft (180 sq ft) | 24 × 24 in | 50 tiles | 5 boxes |
Boxes are different for every tile, some boxes have 5 tiles, some have 20. Always check the number written on your box and type that number above.
1. Forgetting the 10% extra. Tiles get cut at every wall and corner, and a few always break. This calculator already adds 10%. For a diagonal (diamond) pattern, buy 15% extra instead, diagonal cuts waste more.
2. Mixing feet and inches. Room size goes in feet, tile size goes in inches. Mixing them gives a completely wrong answer, here each box is clearly labelled, so this cannot happen.
3. Guessing the box count. Two tiles that look the same can come in very different box sizes. Read the box, do not guess.
4. Buying everything in one go with no spare box. Keep one extra box after the job. If a tile cracks next year, the same colour and batch may no longer be sold.
5. Measuring only the middle of the room. Rooms are rarely perfect squares. Measure the longest length and the longest width and use those numbers.
98 tiles exact with a 1/8 inch grout gap, and 108 tiles with the standard 10% extra for cuts and breakage. In boxes of 10, that is 11 boxes.
10% extra is the standard for a normal straight pattern. Buy 15% extra for a diagonal pattern or a room with many corners and cuts, because more pieces get wasted.
It is printed on the box, and shops also write how many square feet one box covers. If one box covers 10 sq ft and your room is 100 sq ft, you need 10 boxes exact, 11 with the 10% extra.
Yes, a little. A wider gap means each tile covers slightly more area, so you need slightly fewer tiles. The difference is small, but this calculator includes the gap so the answer is honest.
Yes. Instead of room length and width, type the wall's width and height in feet. The same formula works for walls and floors.