Enter your room size and tile size to find out exactly how many tiles and boxes you need — with a waste factor and total cost. Works for floors, walls, backsplashes, and showers.
The method is simple: tiles needed = area to tile ÷ area of one tile, then add a waste allowance for cuts and breakage. This calculator does the math for you and also works out how many boxes to buy and the total cost so you don't make a second trip to the store — or end up with a pile of leftover tile.
1. Area = length × width of the floor or wall.
2. Area of one tile = tile width × tile height (converted to the same units).
3. Bare tile count = area ÷ tile area.
4. With waste = bare count × (1 + waste % ÷ 100), rounded up.
Always buy extra — you will cut tiles at edges and some will break. A good rule of thumb: 10% for a standard straight layout, 15% for diagonal or herringbone patterns, and up to 20% for rooms with lots of corners, niches, or for natural stone, which varies more. Keeping a few spare tiles after the job is also smart for future repairs, since dye lots change over time.
| Tile size | Area each | Common use |
|---|---|---|
| 3 × 6 in (subway) | 0.125 sq ft | Backsplashes, walls |
| 12 × 12 in | 1.0 sq ft | Floors, walls |
| 12 × 24 in | 2.0 sq ft | Floors, large format |
| 18 × 18 in | 2.25 sq ft | Floors |
| 24 × 24 in | 4.0 sq ft | Floors, modern look |
| 6 × 24 in (plank) | 1.0 sq ft | Wood-look floors |
Grout lines are thin enough that they don't meaningfully change the tile count, so this calculator ignores them. But if you're tiling a wall with a large window or a floor around a kitchen island, subtract those areas from your length × width before calculating — or just rely on the waste factor to absorb small openings.