How to determine the size of texture?


I’m fairly new to blender and 3D in general. I’m currently working on a project of a airport and I’m just starting to texturing. The problem I’m facing now is what size do the textures have to be or put another way how does blender size a texture to an object?
Is a pixel in the texture equals a certain blender unit? This is of course when the mapping parameter is set to a size of 1.

See the 2d link in the first post in this thread:


Size does count :yes:

for real time rendering I go by 1 pixel to 1 imperialistic inch at the very minimum.