Real size of a texture

how do you tell Blender the size of tiles e.g. in a floor object. I have e.g. a bathroom floor which should be made of distinct 30 by 60 cm (well 0.3 by 0.6 BU) tiles. Is the only way to divide the objects X and Y dim by the tile X and Y dim and put this into texture mapping size X and Y? This gives you not precise control.


You could make the object 30x60 then UV wrap the texture.