3D Tool

I know it would be better if I posted my question in a more relevant forum, but I think here I’ll find answers from more serious and professional guys.
I’m designing a 3d level editor using OpenGL. How should I correctly display a grid in orthographic view so that it refelcts the correct measures? Is there any tutorials that describes the exact behaviour of a grid?

Thanks.

As long as you make the grid and your geometry follow the same sizing rules, then displaying the grid however you want is fine.