Stack-up of multilayer PCB:
The shown stack-up is used as a standard for 12-layer boards with a thickness of 1.9 mm, if nothing else is descibed by the PCB specification.
The calculated thickness may vary with the copper fill degree of the inner layers.
If the inner layers are almost full copper (like power and ground planes) the full copper thicknesses must be taken into account when calculating the board thickness.
On the other hand, a signal layer with just a few tracks have little effect on the board thickness.
In all shown examples the thicknesses are calculated as having two power/ground layers and remaning layers as signal.
We are always available for advice regarding stack-ups.