Couldnt find this anywhere so asking (sorry if I missed it and has already been asked)
First post here (in a long while) so HI 
I have a mesh that I do not want dynameshed or Zremeshed. It is currently at 7million which is too low and, upon subdividing, shoots up to 30 million~. 14million would be an idea number; is there any way to set how many subdivisions are added when dividing once>?
Thanks
No, it is a fixed proportion. You could subdivide only part of the mesh and this would give you smaller number but usually is not great as it creates triangles. You could also freeze subdivisions and optimize the mesh with zmodeler with the lower subdivision.
A rough rule of thumb for subdividing is that each subdivision multiplies by 4. So your 7 million would become over 28 million at the next level.