Mosaic tile is made up of individual tesserae in 1 inch by 1 inch squares.
Bathroom wall tile sizes standard.
Tiles that are 12 inches high by 24 inches long work well if you want larger sized tiles.
Tile comes in a variety of sizes but there are several standard sizes that complement most wall designs.
Rectangular shaped tiles comes a in a range of different sizes though the most standard options are as follows.
30x90 cm tiles 30 90 is a rectangular size that constitutes an alternative to the traditional square sizes of ceramic tiles.
With your suggestion of 300x600 on wall and 300x300 on floor each pair of floor tiles will have a grout line so you would need to have wider grout lines on wall or end up with them not quite matching.
Guide to wall and floor tile sizes.
This size can be laid in lines or staggered combined in a modular way with the 90 90 size or used for walls.
6 8 and 8 10 wall tile sizes are typical in bathroom installations these days but we are also seeing more homeowners use 12 12 and 12 24 floor tiles on walls too.
Bathroom wall tile sizes similar to shower walls bathroom walls usually look best with tiles above the 4 inch by 4 inch size.
As previously mentioned large format wall tiles are becoming increasingly popular.
Since bathroom walls can be longer than they are high you can use tiles that also are longer than they are high.
Not a problem if you run the rectangles vertically.
1 x2 3 and 4 2 x3 4 5 6 and 8 3 x4 5 6 and 8 4 x4 5 5 6 and 8 5 x2 3 4 6 and 8 6 x8.
Porcelain planks are also a popular choice for bathroom walls.
1 inch by 2 inch mosaic subway blend.
Hope that makes sense.