Tile Calculator
How many tiles for a 10x10 floor?
A 10 x 10 ft floor is 100 sq ft. With 12 x 12 in tile and a 1/8 in grout joint, each tile covers 1.021 sq ft, so you need about 98 tiles before waste and 108 with 10% waste. With 12 x 24 in tile it is 55 tiles, and with 24 x 24 in tile it is 28.
This tile calculator tells you how many tiles you need for a floor, wall, shower or backsplash. Enter the area in feet or as total square feet, choose a tile size and grout width, and it counts the tiles, adds your waste allowance, and rounds up to whole tiles.
It is meant for DIYers planning a bathroom or kitchen and for anyone checking a contractor quote. Add the number of tiles per box and a price per tile, and it also tells you how many boxes to buy and what the tile itself will cost.
Enter your details
How to Use the Tile Calculator
- 1
Enter the area
Choose Length × Width and type the room size in feet, or choose Square Feet and enter the total area you already know.
- 2
Pick a tile size
Select a common size from 2 × 2 in mosaic up to 24 × 24 in, or choose Custom Size and type the tile length and width in inches.
- 3
Set grout and waste
Choose a grout width from 1/16 in to 3/8 in and a waste factor of 5, 10, 15 or 20 percent.
- 4
Add box and price details (optional)
Enter tiles per box and price per tile to see the number of boxes to buy and an estimated tile cost.
How the tile calculator works
Each tile covers its own face plus one grout joint on two sides, so the tool adds the grout width to both tile dimensions before working out the area per tile. It divides your floor or wall area by that figure, adds the waste percentage, and rounds up to the next whole tile.
Tile dimensions are in inches and the area is in square feet, which is why the tile area is divided by 144 (square inches in a square foot). The defaults are a 12 × 12 in tile, 1/8 in grout and 10 percent waste.
Tile coverage (sq ft) = (tile length + grout) × (tile width + grout) ÷ 144; Tiles needed = round up [area ÷ tile coverage × (1 + waste % ÷ 100)]; Boxes = round up (tiles needed ÷ tiles per box)Worked example: a 10 × 12 ft bathroom floor
You are tiling a 10 × 12 ft floor with 12 × 12 in tile, 1/8 in grout and a 10 percent waste factor. The tile comes 15 to a box.
- Floor area: 10 × 12 = 120 sq ft.
- Tile plus grout: 12.125 × 12.125 = 147.02 sq in, and 147.02 ÷ 144 = 1.021 sq ft per tile.
- Tiles before waste: 120 ÷ 1.021 = 117.54, shown as about 118.
- Add 10 percent: 117.54 × 1.10 = 129.29, rounded up to 130 tiles.
- Boxes: 130 ÷ 15 = 8.67, rounded up to 9 boxes.
Tiles per square foot by tile size
These figures assume a 1/8 in grout joint, the calculator default. The last column rounds up after adding 10 percent waste. Small mosaics are usually sold on mesh sheets, so buy those by the square foot rather than counting pieces.
| Tile size (in) | Sq ft per tile | Tiles per sq ft | Tiles per 100 sq ft + 10% |
|---|---|---|---|
| 4 × 4 | 0.118 | 8.46 | 931 |
| 6 × 6 | 0.261 | 3.84 | 423 |
| 8 × 8 | 0.458 | 2.18 | 240 |
| 12 × 12 | 1.021 | 0.98 | 108 |
| 12 × 24 | 2.031 | 0.49 | 55 |
| 18 × 18 | 2.281 | 0.44 | 49 |
| 24 × 24 | 4.042 | 0.25 | 28 |
Tiles needed for common room sizes
Counts use the calculator defaults of a 1/8 in grout joint and 10 percent waste, rounded up to whole tiles. The last column is 12 × 12 in tile at the 20 percent diagonal setting.
- Tile is sold by the box, and box counts vary by product. Enter the tiles per box from the carton and the calculator rounds up to whole boxes; for example 108 tiles at 15 per box is 8 boxes.
- The grout joint is added to each tile's size before dividing, so these counts are a little lower than dividing the area by the bare tile size. For 12 × 12 in tile on 100 sq ft, the bare-tile method gives 111 tiles with 10 percent waste, against 108 here.
| Floor | Area | 6 × 6 in | 12 × 12 in | 12 × 24 in | 18 × 18 in | 24 × 24 in | 12 × 12 in diagonal (20%) |
|---|---|---|---|---|---|---|---|
| 5 × 8 ft | 40 sq ft | 169 | 44 | 22 | 20 | 11 | 48 |
| 10 × 10 ft | 100 sq ft | 423 | 108 | 55 | 49 | 28 | 118 |
| 12 × 12 ft | 144 sq ft | 609 | 156 | 78 | 70 | 40 | 170 |
| 12 × 14 ft | 168 sq ft | 710 | 182 | 91 | 82 | 46 | 198 |
| 14 × 16 ft | 224 sq ft | 946 | 242 | 122 | 109 | 61 | 264 |
| 20 × 20 ft | 400 sq ft | 1,689 | 431 | 217 | 193 | 109 | 471 |
Choosing a waste factor
Waste covers cut pieces at walls, breakage and a few spares for future repairs. The calculator offers four settings: 5 percent for a simple, straight layout in a square room, 10 percent as the everyday standard, 15 percent for rooms with many corners, cabinets or a toilet and tub to cut around, and 20 percent for diagonal patterns.
Large-format tiles waste more per cut, because an offcut is often too small to reuse. Herringbone and other patterns with many angled cuts usually call for the higher settings too.
Tips for L-shaped rooms, walls and buying tile
- For an L-shaped floor, split it into rectangles, add their areas, and enter the total with the Square Feet option.
- For walls, multiply the width by the height you plan to tile, then subtract large openings such as windows and doors.
- Leave out areas under fixed cabinets or a vanity only if you are sure the tile will not run underneath.
- Buy all boxes from the same production lot, because color and size can vary slightly between lots. Keep a few spare tiles for future repairs.
- The cost shown is for tile only. Thinset, grout, backer board, trim and labor are extra.
Edge cases: diagonal layouts, showers and large-format tile
- Diagonal and herringbone: the tile area does not change, but every edge piece is an angled cut. Use the 15 or 20 percent waste setting; a 10 × 10 ft floor in 12 × 12 in tile goes from 108 tiles at 10 percent to 118 at 20 percent.
- Showers and tub surrounds: tile each wall separately (width × tiled height) and add them, then add the shower floor. Niches, benches and curbs need extra pieces and trim, so lean toward 15 percent waste.
- Mosaics: 2 × 2 in mosaics are sold on mesh sheets, usually about 1 sq ft each. Use the Coverage Needed figure in square feet to count sheets instead of individual pieces.
- Large-format tile (24 in and up): fewer tiles, but each broken or miscut tile costs more and the floor must be flatter. Order at least one spare box.
- Rest of the floor: if tile meets laminate or vinyl plank in an adjoining room, the flooring calculator handles box counts for that area. For L-shaped or odd-shaped rooms, get the area from the square footage calculator and enter it with the Square Feet option.
When to call a professional
A small bathroom floor or kitchen backsplash is a manageable first tile job. Consider a professional for heated floors, steam showers, large-format tile on uneven subfloors, or any shower waterproofing you are not confident about; a leaking shower pan can damage framing and ceilings below long before you notice it. Tiling over a bouncy wood subfloor also tends to crack grout and tile, so have the floor structure checked first. Wall tile in wet areas goes over cement board or a waterproofing membrane, not ordinary drywall.
Features
- Floor and wall calculations
- Multiple tile sizes
- Grout spacing adjustment
- Waste percentage included
Frequently Asked Questions
How many tiles do I need for a 10x10 floor?
A 10 x 10 ft floor is 100 sq ft. With 12 x 12 in tile and a 1/8 in grout joint you need about 98 tiles, or 108 after adding 10 percent waste. With 12 x 24 in tile you need 55, with 18 x 18 in tile 49, and with 24 x 24 in tile 28. A diagonal layout at 20 percent waste raises the 12 x 12 count to 118.
How many tiles do I need for a 10x12 room?
A 10 × 12 ft room is 120 sq ft. With 12 × 12 in tile and a 1/8 in grout joint, each tile covers 1.021 sq ft, so you need about 118 tiles before waste. Adding the standard 10 percent brings it to 130 tiles. With 12 × 24 in tile under the same settings, you need 65 tiles.
How many 12x12 tiles do I need for a 12x12 room?
A 12 × 12 ft room is 144 sq ft. With a 1/8 in grout joint, each 12 × 12 in tile covers 1.021 sq ft, so the bare count is about 141 tiles. Add 10 percent waste and round up, and you should buy 156 tiles. If the layout is diagonal, use 15 to 20 percent waste instead.
How much extra tile should I buy?
Buy about 10 percent extra for a standard straight layout. Go down to 5 percent only for a simple square room with few cuts, and use 15 percent for rooms with lots of corners or obstacles. Diagonal and herringbone layouts often need 15 to 20 percent. Keeping a few leftover tiles also makes future repairs much easier, since discontinued lots can be hard to match.
Does grout width change how many tiles I need?
Yes, a little. Wider joints mean each tile plus its grout covers more area, so you need fewer tiles. For a 120 sq ft floor with 12 × 12 in tile and 10 percent waste, a 1/16 in joint needs 131 tiles, 1/8 in needs 130, 1/4 in needs 127 and 3/8 in needs 125. The effect is bigger with small tiles.
How many 4x4 tiles do I need for a backsplash?
Measure the backsplash width times its height to get square feet. For 30 sq ft of 4 × 4 in tile with a thin 1/16 in grout joint, each tile covers about 0.115 sq ft, so you need about 262 tiles before waste and 288 after adding 10 percent. Subtract outlets and windows only if they are large.
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