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.
Drawdown phase (Entnahmephase)
The period in which money is withdrawn regularly from accumulated capital — and the question of how long it lasts.
In plain language
While saving, capital grows; while drawing down it shrinks — but not as fast as people expect, because the remainder keeps earning interest. What matters is the ratio: if the monthly withdrawal is below the interest, the capital survives. If it is above, it eats into the balance, and eventually the balance is gone. One point is often forgotten: a fixed withdrawal loses a great deal of purchasing power over twenty years. To keep the same real amount you have to raise the withdrawal every year — and then the capital lasts for less time.
In detail
The calculation is made in arrears: in each month the balance first earns interest (annual rate divided by twelve), then the withdrawal is deducted. Where the interest exceeds the withdrawal, the capital keeps growing despite the withdrawals — that case is reported as indefinitely sustainable. A calculation of this kind does not capture two risks: sequence-of-returns risk (weak years at the start of drawdown hurt far more than at the end, because the whole capital is still exposed) and tax — a withdrawal from a securities account attracts Abgeltungsteuer on the gain element, so the gross withdrawal has to be higher than the net amount you want.
Worked example
120.000 € of capital and 1.000 € withdrawn per month: with no interest that lasts exactly 120 months, i.e. ten years. At 4 % interest it covers 153 months of full withdrawals, i.e. 12 years and 9 months, followed by a final payment of 503,37 € — so the interest is worth just under three years. With 500.000 € of capital and 1.000 € withdrawn, the interest carries the withdrawal entirely: the balance is never touched.
In brief
Each month interest first, then the withdrawal; the capital falls as long as the withdrawal exceeds the interest.