Tile Calculator
This tile calculator works out how many tiles and boxes you need for a floor or wall. Enter the room size or the total square feet, pick your tile size, and add a waste allowance for cuts, and you'll get the tile count, the boxes to buy, and the square footage each tile covers. There's no formula to memorize. It's built for floors, walls, showers, and backsplashes alike.
- Tiles for a floor or wall
- Room size or sq ft
- Any tile size
- Waste allowance
- Box count
Last updated July 27, 2026 12×12 in tile ≈ 1 sq ft Built by Muhammad Younus
Enter the area and tile size above 0.
Add 10 percent waste for straight layouts, 15 for diagonal, 20 for herringbone. Keep a spare box for repairs.
120 ft² × 1.10 ÷ 1.00 = 132 tiles
How many tiles do I need?
Tiling comes down to area divided by tile size, with a little extra for cuts. Find the area in square feet, multiply by a waste factor so you don't run short at an edge, then divide by how much one tile covers. A 12 by 12 inch tile is exactly 1 square foot, so a 120-square-foot floor with 10 percent waste works out to 132 tiles. Switch to a smaller 6 by 6 tile and you'll need four times as many, since each one covers a quarter of the area. The calculator handles whatever size you pick the moment you type, so you're not doing the math twice. It's the quickest way to turn a room measurement into a shopping list.
Working out a floor, step by step
Here's how the calculator handles a 10 by 12 foot floor with 12 by 12 inch tiles and 10 percent waste. It's the same path you'd take by hand:
- 1
Find the area10 ft × 12 ft = 120 square feet to cover.
- 2
Add the waste120 × 1.10 = 132 square feet, the cushion for cuts.
- 3
Find one tile area12 in × 12 in = 144 sq in, divided by 144 = 1 square foot per tile.
- 4
Divide and round up132 ÷ 1 = 132 tiles, then 132 ÷ 10 per box = 14 boxes.
Tiles per square foot by size
Here's how many of each common tile fill a square foot, before waste. Larger tiles mean fewer pieces and fewer grout lines, so they're quicker to lay, while small mosaics multiply the count fast and you'll spend longer cutting. If you're between two sizes, this table shows what each choice costs in tile count.
| Tile size (in) | Area each | Tiles per sq ft | Per 100 sq ft +10% |
|---|---|---|---|
| 4 × 4 | 0.11 ft² | 9.00 | 990 |
| 6 × 6 | 0.25 ft² | 4.00 | 440 |
| 12 × 12 | 1.00 ft² | 1.00 | 110 |
| 12 × 24 | 2.00 ft² | 0.50 | 55 |
| 18 × 18 | 2.25 ft² | 0.44 | 49 |
| 24 × 24 | 4.00 ft² | 0.25 | 28 |
How many tiles do I need for common room sizes?
This table runs the count for standard 12 by 12 inch tiles with the usual 10 percent waste, so it's a quick gut check before you open the tool. One-foot tiles cover a square foot each, which keeps the math clean. Enter your own tile size above and the numbers update, but if you're laying one-foot tiles, you can read your answer straight off this list.
| Room size | Area | 12×12 tiles (+10%) | Boxes of 10 |
|---|---|---|---|
| 5 × 8 (small bath) | 40 ft² | 44 | 5 |
| 8 × 10 | 80 ft² | 88 | 9 |
| 10 × 10 | 100 ft² | 110 | 11 |
| 10 × 12 | 120 ft² | 132 | 14 |
| 12 × 15 | 180 ft² | 198 | 20 |
| 15 × 20 (large room) | 300 ft² | 330 | 33 |
Thin grout lines, usually an eighth to a quarter inch, barely change the count, so you can size the job by tile alone.
Frequently asked questions
Take the area you're tiling in square feet, add a waste allowance for cuts and breakage, then divide by the square footage of one tile. A 12 by 12 inch tile is exactly 1 square foot, so a 120-square-foot floor with 10 percent waste needs 132 tiles. This tile calculator runs that math the second you type, so you'll know the count and the boxes before you head to the store.
Multiply the tile's width and height in inches, then divide by 144 to get its area in square feet, and 1 divided by that is tiles per square foot. A 12 by 12 tile is 144 square inches, so 1 square foot, which means 1 tile per square foot. A 6 by 6 tile is 0.25 square foot, so you'll fit 4 per square foot. The calculator shows this figure for whatever size you enter.
Ten percent is the standard cushion for a straight layout, and it covers cuts, edges, and the odd cracked tile. Bump it to 15 percent for a diagonal or herringbone pattern, since angled cuts waste more, and go to 20 percent for a busy room with lots of corners. Some folks call this the overage, but it's the same thing, extra tile so you don't run short mid-job. The waste box above defaults to 10, so you can dial it to match your pattern.
Measure the room in feet and multiply length by width, so a 10 by 12 room is 120 square feet. For the tile itself, multiply its width and height in inches and divide by 144, since a square foot holds 144 square inches. That means a 12 by 12 tile covers 1 square foot, while an 18 by 18 covers 2.25. Divide the room's square footage by one tile's, add your waste, and that's the count. Our square footage calculator handles odd-shaped rooms if you need to add a few rectangles first.
It varies by tile size, but a box of 12 by 12 tiles usually holds 10 to 15, while large-format 24 by 24 tiles often come 3 or 4 to a box. The box always lists the square footage it covers, so check the label and type that count into the tiles-per-box field. Then you'll get the exact number of boxes to buy, rounded up so you don't come up short.
Yes, and the waste percentage handles most of it, but it's smart to keep one spare box too. Dye lots shift between production runs, so a box bought a year later might not match. Tucking away a few tiles from the same lot means a future repair blends in. Round up to whole boxes, which the calculator already does for you.
It does. Measure the wall area the same way, length times height in feet, then enter your tile size and waste. A backsplash or shower wall uses the exact same tiles-per-area math as a floor. For odd shapes, add up the rectangles and tile the total, or use the square footage calculator first to nail down the area.
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