So, as we all know, Hitler wanted to do a certain two things- a) expand the German people east, and b ) encourage so-called "aryan peoples" to prosper demographically. Both of these will generally involve having large families to birth more Germans, which Hitler was certainly in favour of. In fact, Hitler once said in a speech that if he was presented with a female lawyer and a woman with six healthy children, he would prefer to have the mother. It's pretty obvious that this means Hitler was in favour of having his people make lots and lots of Germanic children.
Now, hypothetically, let's say the Nazis win WW2. Germany's lost a lot of men and the ones that do come home will start a baby boom. The amount of settlement planned in the east is enormous, and the government is encouraging birth-rates as well.
Provided a Fatherland-esque scenario happens after WW2, much will a victorious Nazi Germany's population grow? How big might they be by 1960? By the end of the 20th century? By 2016?