Number format: this calculator uses German notation throughout — a comma is the decimal separator and a dot groups thousands. “1.234,56” means one thousand two hundred thirty-four euros and fifty-six cents. The figures come from German tax law, so they are shown the way German authorities write them.
Follow-on financing (Anschlussfinanzierung)
Financing the remaining debt once the fixed-rate period ends — at whatever rate applies then.
In plain language
Most German mortgages have a rate that is fixed only for a set period — often ten years. After that the loan is usually not repaid: a residual debt remains, and you need a new contract for it. Nobody knows today what that will cost. So it is worth working through what happens if the rate is much higher than today. If you can carry that, your figures are sound.
In detail
When the fixed-rate period (Sollzinsbindung) ends, the rate commitment ends — not the loan. The residual debt continues either as a prolongation with the same bank or as a switch to another; the rate follows whatever the market offers then. To keep the residual debt small, raise the initial repayment rate or make overpayments. A full-repayment loan (Volltilgerdarlehen) removes the interest-rate risk entirely, because the loan is fully repaid when the fixed period ends — at the price of a higher instalment. A forward loan secures the follow-on rate in advance, for a premium.
Worked example
250.000 € at 3,75 % with 2 % initial repayment: after a ten-year fixed period 189.447,36 € is still outstanding. Continued at 5,5 % over the remaining 219 months, the instalment rises from 1.197,92 € to 1.374,43 € — some 177 € more per month. If the rate stayed at 3,75 %, the instalment would stay as it is. A full-repayment loan over ten years would have needed an instalment above 2.500 €, but nothing would be left outstanding.
In brief
The debt outstanding at the end of the fixed-rate period becomes a new loan over the remaining term, at the future interest rate.