Germany: the Rentenversicherung is the larger part
The German gesetzliche Rentenversicherung provides most retirement income in Germany and is not modelled here. That is the first thing to know before reading anything below: for a typical German employee the statutory pension, not a private portfolio, is the main source of retirement income, and the balance projected on this page is the top-up rather than the plan.
The Regelaltersgrenze, the standard pension age, reaches 67 for those born in 1964 or later, which is where the retirement age opens. Earlier cohorts reach it sooner on a birth-year timetable, so if you were born in the 1950s your own age is lower and worth entering.
Because the statutory pension is earnings-related and rests on a contribution history this calculator never asks for, the honest way to use the tool in Germany is backwards. Take the projected Rente from your annual Renteninformation, subtract it from the income you actually want, and enter only the remainder as the income target. Skip that step and the target here will be far larger than you need, at a 3.5% withdrawal rate, every €1,000 a year the statutory pension covers is €28,571 you do not have to accumulate yourself.
The German assumptions are a 6.5% nominal return and 2% inflation, which is a real return of 4.41% a year.