Tile Calculator
A 10 by 12 ft room needs 132 tiles when you use 12 by 12 in tile with 10% waste. That sounds simple, but real tile jobs get messy fast. Doorways steal full pieces. Diagonal layouts create more cuts. Showers and backsplashes add outlets, niches, and edges that increase breakage and offcuts. This tile calculator starts with the core math you actually need for ordering. Enter the installation width and length in feet, enter the tile size in inches, choose a waste percentage, and the tool returns the estimated tile count, area, and coverage per tile so you can sanity check the order before you buy.
Quick answer
The calculator finds the installation area in square feet by multiplying width by length.
What this tells you
- •The calculator finds the installation area in square feet by multiplying width by length.
- •It converts one tile from inches to square feet so the tile area matches the room area.
- •It divides area by tile area, applies waste for cuts and breakage, and rounds up because tile is bought as whole pieces.
How to Use
- 1Measure the longest width and length of the tile area in feet. For a simple floor, that is usually wall to wall. For a shower wall or backsplash, measure only the section that actually receives tile.
- 2Enter the tile width and tile length in inches. A 12 by 24 tile covers twice the area of a 12 by 12 tile, so size matters as much as room dimensions.
- 3Set the waste percentage based on the layout. About 10% works for many straight set jobs. Diagonal patterns, narrow rooms, herringbone layouts, and walls with many cutouts often need 12% to 15% or more.
- 4Click Calculate to see the tile count. Use the area and tile area results to double check that the numbers pass a quick smell test before ordering.
How It Works
Formula
Area ft2 = Width ft x Length ft
Tile ft2 = (Tile Width in x Tile Length in) / 144
Tiles Needed = ceil((Area ft2 / Tile ft2) x (1 + Waste%))Width times length gives total area in square feet. Tile dimensions are entered in inches, so the calculator converts each tile to square feet by dividing by 144. It then divides the project area by one tile's coverage, adds waste, and rounds up to a whole tile because you cannot order 131.2 tiles.
Calculation note: values are processed in the order shown above, using the current input units.
Worked Examples
Kitchen floor with standard 12 by 12 tile
The floor area is 10 x 12 = 120 sq ft. Each 12 x 12 in tile covers 1 sq ft. The base count is 120 tiles, and adding 10% waste brings the order to 132 tiles.
Bathroom floor with large format 12 by 24 tile
The floor area is 80 sq ft. A 12 x 24 in tile covers 2 sq ft, so the raw count is 40 tiles. A 12% waste factor raises the order to 44.8, which rounds up to 45 tiles. That extra margin helps when the layout starts with a centered pattern or when walls are not perfectly square.
Backsplash with small subway tile
A long backsplash at 15 ft by 1.5 ft covers 22.5 sq ft. One 3 x 6 in subway tile covers 0.125 sq ft, so the base count is 180 tiles. A 15% waste factor raises that to 207 tiles, which is realistic once you account for outlet cuts, end cuts, and matching the layout under cabinets.
Mudroom with 6 by 24 in wood-look plank tile
Priya is tiling a 6 ft by 9 ft mudroom with 6 by 24 in plank tile in a staggered layout. The floor is 54 sq ft and each plank covers exactly 1 sq ft, so the base count is 54. She sets waste at 12% rather than 10% because every row of a staggered pattern starts with a cut piece, and the calculator returns 54 x 1.12 = 60.48, rounded up to 61 tiles. At 10% waste the answer would be 60, a one-tile difference that only matters if the carton count changes with it.
Tiles needed per 100 sq ft by tile size
Whole tiles for a 10 ft by 10 ft area at the tool's default 10% waste and at the 15% setting suggested for diagonal and cut-heavy layouts. Scale the count for your area, then round up to full cartons.
| Tile size (in) | Tile area (sq ft) | Tiles, no waste | Tiles at 10% waste | Tiles at 15% waste |
|---|---|---|---|---|
| 3 x 6 subway | 0.125 | 800 | 881 | 920 |
| 6 x 6 | 0.25 | 400 | 441 | 460 |
| 8 x 8 | 0.4444 | 225 | 248 | 259 |
| 12 x 12 | 1 | 100 | 111 | 115 |
| 6 x 24 plank | 1 | 100 | 111 | 115 |
| 6 x 36 plank | 1.5 | 67 | 74 | 77 |
| 12 x 24 | 2 | 50 | 56 | 58 |
| 18 x 18 | 2.25 | 45 | 49 | 52 |
| 24 x 24 | 4 | 25 | 28 | 29 |
| 24 x 48 | 8 | 13 | 14 | 15 |
Computed with the formula above for a 10 ft by 10 ft entry: tile area = width x length / 144, tiles = ceil(100 / tile area x (1 + waste)). Tile sizes are nominal face dimensions. The 10% and 15% waste figures are this page's planning conventions, not a published standard.
What This Tile Estimate Assumes
This calculator assumes the full measured width and length receive tile and that every tile in the field is the same nominal size. It treats the job as one simple rectangle, which is the right starting point for ordering but not the final layout plan. If your room has a tub deck, kitchen island, closet notch, bench, or stair return, measure those sections separately and add or subtract area before you buy.
It also assumes your waste setting covers the real job conditions. That is the big judgment call. A straight grid on a square laundry room wastes less than a diagonal porcelain floor in a hallway that pinches down at one end. The math is identical. The offcuts are not. If you know the space is awkward, trust that and raise the waste percentage instead of pretending the room is friendlier than it is.
Tile is also sold in boxes, not loose pieces, in many stores. If your result says 132 tiles and the product comes 10 pieces per box, you still need to round up to full cartons when you place the order. Use this calculator to get the piece count first, then compare that number with the box coverage or carton quantity on the product sheet.
Layout rules change how much waste you generate, and two documents set those rules in North America. The TCNA Handbook for Ceramic, Glass, and Stone Tile Installation, published by the Tile Council of North America, is the installation method reference. ANSI A108, A118, and A136.1 are the installation and material specifications it points to. ANSI A108.02 sizes the grout joint at three times the actual variation in the tile's facial dimensions, never under 1/16 in, and for a running bond with any tile side over 15 in it limits the offset to 33% of the tile length with a wider minimum joint, 1/8 in for rectified tile and 3/16 in for calibrated tile. ANSI A137.1 sets the size and warpage tolerances that feed those joint widths. None of this changes the tile count directly, because the calculator uses face dimensions without joints, but a one-third offset on a 24 by 48 in tile means more and longer cut pieces at every wall than a straight grid, so give it a higher waste setting.
Common mistakes
- Using the outside room dimensions even when cabinets, islands, tubs, or vanities reduce the actual tile area
- Keeping waste at 10% for a diagonal, herringbone, or cut-heavy layout that clearly needs more margin
- Mixing feet for the room and inches for the tile without converting units, which can blow up the tile count
- Ordering the exact piece count without checking how many tiles or square feet come in a full box
- Forgetting to keep spare attic stock for future repairs when the tile may be discontinued later
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