Diagonal sets cut every edge tile at 45 degrees. Waste jumps to 15-18%. Running short on a diagonal install is especially painful since the angle-cut offcuts cannot be reused easily.
Tile Calculator: Tile Count, Cartons & Waste Factor
Estimate tile count, cartons, and waste-adjusted order for floors, walls, showers, and backsplashes.
Default settings
- Default waste is 10% and should be increased manually for diagonal, herringbone, or highly cut layouts.
- Tile coverage uses face area only and does not add grout-joint math.
- Boxes stay optional because many users first need a piece count before they know the carton size.
How this estimate works
- Net area = room length x room width, or manual measured area
- Tile coverage per piece = tile length x tile width converted into square feet
- Raw tile count = net area / tile coverage
- Recommended order = raw tile count x (1 + waste percent), then round up to a whole tile
- Boxes needed = rounded-up tile order / pieces per box when carton size is provided
Related pages
Use a guide if waste or layout needs a closer look.
How these estimates workSee how unit conversion, rounding, and default settings affect the estimate.Tile layout and waste guideChoose a smarter waste factor for straight, diagonal, offset, and herringbone layouts.Flooring waste factor guideCompare tile-specific waste with the broader flooring order guidance.Flooring calculatorUse this when you only need area and box math without tile-piece sizing.
FAQ
Quick answers if you need them.
Why is waste not automatic by layout pattern?
Layout stays explicit instead of guessed. Use the waste guide if the pattern adds more cuts.
Does this include grout or thinset?
No. This page only estimates tile quantity so the order math stays easy to follow.
How the tile estimate is calculated
The five-step math behind tile count, carton count, and waste.
- Net area = room length x room width, or your measured total area.
- Coverage per tile = tile length x tile width, converted to square feet (or square meters).
- Raw tile count = net area / coverage per tile.
- Recommended order = raw count x (1 + waste percent), rounded up to whole tiles.
- Boxes needed = order / pieces per box, rounded up. Only calculated if box size is provided.
The calculator uses tile face area only - grout joints are not subtracted. That is the right approach for ordering: grout joints reduce visible tile but do not change tile count.
Tile size reference and typical waste
Common tile sizes, coverage per piece, and the waste factor each typically needs.
| Tile size | Coverage per piece | Recommended waste | Best for |
|---|---|---|---|
| 1 x 1 in mosaic (on mesh) | varies by sheet | 10-12% | Showers, accents |
| 3 x 6 in subway | 0.125 sq ft each | 10% | Backsplashes, shower walls |
| 6 x 6 in | 0.25 sq ft each | 10% | Smaller bathroom floors |
| 12 x 12 in | 1 sq ft each | 10% | Bathrooms, kitchens |
| 12 x 24 in | 2 sq ft each | 10-12% | Modern floors, large spaces |
| 18 x 18 in | 2.25 sq ft each | 10-12% | Kitchens, living areas |
| 24 x 24 in | 4 sq ft each | 12-15% | Large open spaces |
| 9 x 48 in plank | 3 sq ft each | 12-15% | Wood-look floors |
Worked examples by project type
Four common tile projects with tile counts and box totals worked out.
| Project | Dimensions | Net area | Raw count | With waste | Boxes |
|---|---|---|---|---|---|
| Bathroom floor | 8 x 6 ft, 12 x 12 in tile | 48 sq ft | 48 tiles | 53 tiles (10% waste) | If 10 tiles/box: 6 boxes |
| Kitchen floor | 12 x 14 ft, 18 x 18 in tile | 168 sq ft | 75 tiles | 83 tiles (10% waste) | If 8 tiles/box: 11 boxes |
| Shower wall | 5 x 8 ft wall, 3 x 6 in subway | 40 sq ft | 320 tiles | 352 tiles (10% waste) | If 80 tiles/box: 5 boxes |
| Herringbone backsplash | 18 sq ft, 3 x 12 in tile, herringbone | 18 sq ft | 72 tiles | 86 tiles (20% waste for herringbone) | If 30 tiles/box: 3 boxes |
Layout patterns and how they change your order
The pattern decision is set before you buy. Choose carefully.
Straight set (grid): the default. Tiles align with the room walls and each other. 10% waste. Easiest install, cleanest math, most common look.
Brick / offset: rows shift by 1/3 or 1/2 tile width. Same 10% waste in most cases. Hides minor wall imperfections better than grid. Standard for subway tile on walls.
Diagonal (45°): the field is rotated 45 degrees from the walls. Every edge tile needs an angle cut, pushing waste to 15-18%. Visually larger-looking room.
Herringbone: rectangular tiles set in a V-pattern. Each tile gets two cuts. Waste jumps to 17-20%. Hard install, premium look.
Versailles / Random: multiple tile sizes in a repeating pattern. Order each size by its share of the pattern; 15% waste minimum.
Common mistakes that ruin a tile order
Five mistakes that send tile installers back to the showroom mid-project.
Plank tiles (6 x 36, 9 x 48) installed parallel to a wall cut differently than installed perpendicular. The waste factor is similar but the cut PATTERN differs - sketch your layout before ordering.
Field tile is just the body. Outside-corner bullnose, jolly trim, mosaic accent strips, and pencil rail are separate orders. Budget them now or get hit later.
Even within one order, mixed lots are common. Check every box's lot number at delivery and stage tiles from different boxes together so the floor blends evenly. Refuse delivery if lots are mixed.
Tile material is one cost. Thinset mortar, grout, backerboard, and waterproofing add 20-40% to the project cost - calculate those separately based on coverage rates printed on the product.
Frequently asked questions
The questions DIY tilers and pros ask most often before ordering.
How many 12 x 12 inch tiles do I need for a 100 sq ft floor?
A 12 x 12 inch tile covers exactly 1 square foot. For 100 sq ft of floor at 10% waste, you need 110 tiles. If your cartons hold 10 tiles each, that is 11 boxes. For non-standard tile sizes the math changes - the calculator handles unit conversion automatically; just enter tile length and width in inches or centimeters.
What waste factor should I use for tile?
10% is the standard for a rectangular floor with straight-set tiles. Bump to 15% for diagonal sets, since every edge tile gets two angled cuts. Use 17-20% for herringbone or pinwheel patterns. Add 5% extra if you are a first-time tile installer - the learning curve produces broken tiles and miscuts. Subway tile on a wall stays at 10% in most cases.
Do I need extra tile for repairs?
Yes - at least one full box of attic stock. Tile dye lots vary visibly between production runs, and a chipped tile replaced from a different lot will look wrong. One box (typically 8-15 tiles for floor sizes) covers normal repairs for the life of the floor. Bathroom installations especially benefit from extra since chips around toilets and tubs are common.
How does tile size affect waste?
Larger tiles (18 x 18 or bigger) often need slightly more waste percentage because each cut wastes more material - one bad cut on a 24 x 24 tile is 4 sq ft gone. Smaller tiles (subway, mosaic, 6 x 6) waste less per cut but introduce more cuts overall. Plank tiles (6 x 36, 9 x 48) sit between - they cut like wood flooring but install like tile.
Should I include grout lines in the calculation?
No. This calculator uses face area only and ignores grout lines, which is the right approach for ordering. Grout lines reduce the visible tile area slightly but do not change how many tiles you need to buy. The waste factor absorbs any small overhead from grout-related cuts.
How do I calculate tile for a shower wall or backsplash?
Measure the wall area (length x height) and subtract any large fixed openings (mirror frame, window). For a typical 5 x 8 ft shower wall with no openings, that is 40 sq ft. At 10-12% waste for a wall install, order ~45 sq ft of tile. Backsplashes are usually 18-30 sq ft and benefit from 12-15% waste because of the many cuts around outlets and edges.
What is the difference between porcelain and ceramic for ordering?
From an ordering standpoint, none - both are calculated the same way by area. The difference is hardness and cost. Porcelain is denser, harder to cut, and pricier; ceramic is easier to work with and cheaper but less durable. Either way, the calculator's tile count is identical. Hire a tile setter who has cut your specific material before if you are going porcelain on large format.
Why does the box count round up so aggressively?
You cannot buy 9.5 boxes of tile. The calculator rounds up to whole cartons, then most installers add one extra. A 9.2-box order becomes 10 boxes ordered, which becomes 11 cartons with attic stock. The math always rounds against you because partial boxes are not a thing, and dye-lot matching after the fact is essentially impossible.
Related calculators and guides
Pages that pair with the tile estimate.
Tile layout and waste guide How layout patterns and room geometry change the right waste percentage. Flooring calculator For laminate, vinyl plank, and hardwood projects. Imperial / metric conversion For European tile sizes in centimeters and meters. How these estimates work Rounding, waste, and unit conversion rules across the site.