Tiling a 12 × 18 ft room with 18″ tile
18" tiles needed
106tiles
237.6 ft² of tile for a 12 × 18 ft room
| Floor area | 216ft² |
|---|---|
| Buy for+10% cuts and breakage | 237.6ft² |
| 18" × 18" tiles | 106tiles |
| Thinset (50 lb bags)45 ft² per bag with a 1/2" × 1/2" square-notch | 6bags |
| Grout (0.125" joints)1 × 25 lb bags | 14.2lb |
- Room width
- 12 ft
- Room length
- 18 ft
- Tile size
- 18 in
Tiles, and then some
The floor is 216 ft². Buying exactly that much is how people end up back at the store: cuts at the walls, the odd broken tile and a spare box for future repairs mean you order 237.6 ft² — 10% over.
At 18″ square that works out to 106 tiles.
Thinset depends on the tile, not the room
This is where rule-of-thumb estimates go wrong. A bigger tile needs a bigger notched trowel, and a bigger notch puts down more mortar per square foot. For 18″ tile you want a 1/2" × 1/2" square-notch, which is why the bag count here is 6 rather than whatever a generic calculator returns.
Before you order
Measure the room at more than one point. Rooms are rarely square, and the widest measurement is the one that decides how many tiles the last row needs.
Notes
- Thinset coverage is set by trowel size, not by room size — a 18" tile needs a 1/2" × 1/2" square-notch, so a 50 lb bag covers about 45 ft².
- Add 15% instead of 10% for a diagonal layout, a room with many jogs, or if the tile has a pattern that has to line up.
- Grout is figured at 0.125" joints and 0.5" tile thickness. Wider joints raise it quickly.
Nearby sizes
- Tiling a 10 × 18 ft room with 18″ tile
- Tiling a 14 × 18 ft room with 18″ tile
- Tiling a 8 × 18 ft room with 18″ tile
- Tiling a 16 × 18 ft room with 18″ tile
- Tiling a 12 × 16 ft room with 18″ tile
- Tiling a 12 × 20 ft room with 18″ tile
- Tiling a 12 × 14 ft room with 18″ tile
- Tiling a 12 × 22 ft room with 18″ tile
- Tiling a 12 × 18 ft room with 12″ tile
- Tiling a 12 × 18 ft room with 24″ tile
- Tiling a 12 × 18 ft room with 8″ tile