One great benefit of using ceramic tile for bathrooms is tile's flexibility. Ceramic and porcelain tiles come in a wide range of sizes, from small mosaic tiles on up to large format tiles as big as 30 inches by 15 inches. This gives you a variety of possibilities when laying tile for your bathroom flooring, walls, and shower and bathtub surrounds.
But this does not mean that you can use all tile sizes for all applications. As an extreme example, large-format tiles often can have an awkward, ungainly appearance in small bathrooms; you need to have a certain number of full-size tiles for the application to visually work.
Yet nothing about bathroom tile sizing is written in stone, and tile sizes stated in this guide are suggestions, not edicts. Experiment with different tile sizes to see what looks best to your eye.
Shower Floor Tile Sizes
For shower floors or pans, generally you will want to have smaller sized tiles, from 4 inches by 4 inches down to 1-inch by 1-inch mosaic tiles. The idea is that you need to have tiles small enough so that the tile installer, while laying the mortar bed, can form gentle contours so that the flooring will pitch correctly and the water will properly move toward a centrally located drain.
Smaller size tiles also work better for shower flooring because they create better grip opportunities for your feet. Smaller tiles mean that the installer must include more seams between the tiles and thus a greater amount of grout laid between those tiles. Grout lines can provide much-needed friction when your feet are moving around on wet flooring.
Shower Wall Tile Sizes
For shower walls, generally it is best to use larger tiles, from 4-inch by 4-inch tiles on upward to large format tiles in the 15-inch by 30-inch range. From a visual standpoint, tile smaller than 4 inches square creates a busy appearance. More importantly, smaller tiles are difficult to clean: More seams mean more grout, and that presents you with that much more grout to contend with.
Large-format tiles up to 30 inches in length usually are the maximum size for alcove bathtubs since those spaces are capped at 60 inches long. If you were to use larger tiles, you would need to cut them. It's easier and more economical to purchase tiles that precisely fit that space.
Bathroom Wall Tile Sizes
Similar to shower walls, bathroom walls usually look best with tiles above the 4-inch by 4-inch size. Since bathroom walls can be longer than they are high, you can use tiles that also are longer than they are high. Tiles that are 12 inches high by 24 inches long work well if you want larger sized tiles.
Subway tiles are a perennial favorite in bathrooms as these, too, have a 1:2 size ratio. For the maximum long-but-narrow ceramic tile, consider using listellos. These decorative tiles are often used to delineate two sections of wall tile.
Bathroom Floor Tile Sizes
Bathroom tile flooring presents the greatest range of tile size possibilities, from mosaic up to large format tile. Keep friction in mind. Tile manufacturers publish the coefficient of friction (COF) ratings for each tile in their printed and online literature.
Mosaic tile is often used for bathroom flooring because of the superior grip that this tile's seaming provides for both wet and dry feet.
Conventional 12-inch by 12-inch tile is often used on bathroom floors because it is easy to cut on wet tile saws as well as with rail tile cutters. Tile of this size also means that you will end up with a decent number of full-size tiles even in the smallest bathroom. With that in mind, 4-inch by 4-inch tile, too, visually works well in small bathrooms and powder rooms.
If you want to have large format tile in your bathroom, first calculate your bathroom's square footage. This will help you determine how many full-size tiles you will end up with. One example of a good layout for large format tile in a small bathroom would be four tiles down the length of the bathroom and three across the width. Less than three tiles across the width can look awkward, especially if you need to cut any of these tiles down.