Wall Tile Calculator
Tiles for bathroom walls, showers and backsplashes
A 10 by 8 ft bathroom tiled 8 feet high in 3 by 6 inch subway tile needs 2,140 tiles and 4 bags of adhesive, after deducting a door and a window and adding 10% waste. Tiling walls is not the floor calculation: the area is the perimeter times the height, less every opening. Enter your room or a single wall, in feet or metres.
How to calculate wall tiles
This wall tiles calculator works as a bathroom wall tile calculator, a backsplash tile calculator or a general wall tiling calculator. Whatever you call it, the tile calculator for walls follows the same three steps, and the third is the one people skip.
- Find the wall area. For a whole room it is perimeter × height, or 2 × (length + width) × height. For one wall it is simply length × height.
- Subtract the openings. Every door and window is area you do not tile, and on a small bathroom they can be 10% of the total.
- Add waste for cuts, usually 10%, or 15% around awkward fittings.
Then set Tile size to what you are actually buying. Walls are rarely tiled in squares: the default here is subway tile at 3 × 6 in (7.5 × 15 cm), and metro, brick-bond, 10 × 20 cm and large-format 30 × 60 cm rectangles are all in the list, with Custom for anything else. Size changes the count enormously — the same shower wall takes nearly eight subway tiles for every one 30 cm square — so it is worth getting right before you order.
Standard deductions used above: a door is taken as 17.5 ft² (1.63 m²) and a window as 12 ft² (1.11 m²). If yours differ noticeably, adjust the count or the waste percentage to compensate.
Wall area by room size and ceiling height
Gross wall area before any openings are deducted, for a rectangular room tiled floor to ceiling.
| Room size | Perimeter | 8 ft ceiling | 9 ft ceiling | 2.4 m ceiling |
|---|---|---|---|---|
| 5 × 8 ft | 26 ft | 208 ft² | 234 ft² | 19.0 m² |
| 6 × 8 ft | 28 ft | 224 ft² | 252 ft² | 20.5 m² |
| 8 × 10 ft | 36 ft | 288 ft² | 324 ft² | 26.3 m² |
| 10 × 12 ft | 44 ft | 352 ft² | 396 ft² | 32.2 m² |
| 12 × 12 ft | 48 ft | 384 ft² | 432 ft² | 35.1 m² |
Worked example: a 3 × 4 m bathroom
Tiled floor to ceiling at 2.4 m, with one door and one window.
| Step | Working | Result |
|---|---|---|
| Perimeter | 2 × (3 + 4) | 14 m |
| Gross wall area | 14 × 2.4 | 33.6 m² |
| Less door and window | −1.63 −1.11 | 30.9 m² |
| Plus 10% waste | 30.9 × 1.10 | 33.9 m² |
| 30 × 30 cm tiles, 3 mm joint | 33.9 ÷ 0.0918 | 370 tiles |
| 60 × 60 cm tiles, 3 mm joint | 33.9 ÷ 0.3636 | 94 tiles |
Ignoring the door and window would have added 2.7 m², or about 30 extra 30 cm tiles. On a bigger job that error compounds quickly. The last two rows are the same wall in two different tiles — switch Tile size above between 30 × 30 cm and 60 × 60 cm, with the joint left at 3 mm, to see each one. Set the joint to none and they read 378 and 95, which is what a face-area-only calculator would tell you.
Half-height, splashback and feature walls
Not every bathroom is tiled to the ceiling. Use the single-wall mode and enter the tiled height rather than the ceiling height:
| Job | Typical height | Note |
|---|---|---|
| Kitchen backsplash | 18 to 24 in (45 to 60 cm) | Worktop to wall unit |
| Bath splashback | Bath rim + 12 in | Extend past the tap end |
| Half-height wall | 36 to 48 in (0.9 to 1.2 m) | Finish on a whole tile course |
| Shower enclosure | 72 to 84 in (1.8 to 2.1 m) | Tile above the shower head |
| Full height | Floor to ceiling | Easiest to plan, most tile |
Where a tiled area stops partway up a wall, plan the run so it ends on a full tile course rather than a thin sliver. Adjust the height by an inch or two rather than cutting a 20 mm strip along the top edge.
Wall tile vs floor tile
They are not interchangeable and the difference matters more going the wrong way. Wall tiles are thinner and lighter so they can hang on adhesive; they are not rated for foot traffic and will crack underfoot. Floor tiles can go on a wall, but the extra weight demands the right adhesive and a substrate that can carry it.
Check the PEI rating: PEI 0 or 1 is wall-only. Anything you walk on wants PEI 3 or higher. In a shower, also check water absorption, where porcelain outperforms most ceramic.
Adhesive, backer board and waterproofing
A 50 lb bag of thinset covers roughly 85 ft² with a 1/4 in notch, dropping to about 40 ft² with the 1/2 in notch large tiles need. Behind a shower or bath, tile over cement backer board or a waterproofing membrane, never plain plasterboard. Work out the joints with the grout calculator, and the floor separately with the tile calculator.
Wall tiling mistakes
- Tiling the full rectangle. Doors and windows are not tiled; deduct them.
- Using floor area for walls. A 3 × 4 m room has 12 m² of floor but 33.6 m² of wall.
- Wall tile in a shower floor. Too slippery and not rated for traffic.
- Starting from the floor. Floors are rarely level; set a level batten and work up from a full course.
- Slivers at the ceiling. Plan the courses so the top row is a sensible width.
- Plasterboard behind a shower. Use backer board or a membrane, or the wall fails.
What the wall tile count assumes
Wall area is perimeter × tiled height (or a single wall's length × height), minus every opening — the step most calculators omit.
- Standard deductions: a door is taken as 17.5 ft² (1.63 m²), based on a typical 6 ft 8 in × 2 ft 8 in leaf, and a window as 12 ft² (1.11 m²). Adjust the counts if yours differ noticeably.
- Adhesive assumes roughly 85 ft² per 50 lb bag at a 1/4 in notch; large-format tile needs a 1/2 in notch and covers closer to 40 ft².
- Tile counts use each tile's laid pitch (face plus grout joint), with metric and imperial sizes handled separately, as on the tile calculator.
Both unit systems. Metric mode takes metres and returns metric units throughout.
Figures reviewed . Every worked example on this page is checked against the calculator above.
Wall Tile Calculator: frequently asked questions
How do I calculate wall tiles?
Multiply the room perimeter by the tiled height, subtract the area of every door and window, then add about 10% for cuts. For one wall it is just length times height, minus openings.
How many tiles do I need for a bathroom wall?
A 3 by 4 m bathroom tiled to 2.4 m has 33.6 m² of gross wall. After deducting a door and a window and adding 10% waste that is about 33.9 m², which is roughly 378 tiles at 30x30 cm or 95 at 60x60 cm.
Do I subtract doors and windows when tiling walls?
Yes. A standard door is about 17.5 ft² (1.63 m²) and a window about 12 ft² (1.11 m²). On a small bathroom those openings can be 10% of the wall area, which is easily a hundred dollars of tile.
Can I use floor tile on a wall?
Usually yes, but the extra weight needs the right adhesive and a substrate that can carry it. The reverse is not safe: wall tiles are thinner, rated PEI 0 or 1, and crack under foot traffic.
How high should a bathroom splashback be?
A kitchen backsplash is typically 18 to 24 inches from worktop to wall units, a bath splashback about 12 inches above the rim, and a shower enclosure 72 to 84 inches. Set the height so the top row is a full tile rather than a sliver.
How much adhesive do I need for wall tiles?
About one 50 lb bag per 85 ft² with a 1/4 inch notched trowel, falling to roughly 40 ft² per bag with the 1/2 inch notch that large-format tile requires.