A4 is the standard size of a sheet of paper (anywhere but the USA, Canada, Mexico and the Dominican Republic).
In Norwegian, there's an idiom, "The A4 life". It means something like:
You work 8-4 in a fairly common profession, have a house, one or two cars, a spouse, and one or more children. You don't do anything extraordinary, you've settled down, and live life like everyone else.
Note: It doesn't mean you live a boring life, and it's not necessarily negative. It means that on paper, your life is just like everyone else's. Note that the part about having a spouse and children is essential.
Is there a word, idiom or phrase that describes this in English?