📅 Published 19 October 2026 · Updated 24 October 2026
Short answer: take your yearly spending, subtract your state pension, multiply by 25 — that is your target pot. Example: a 30-year-old with €5,000 saved who invests €400/month at 6% (0.5% fees) until 67 builds a pot of roughly €598,000, worth about €287,000 in today's money, supporting ≈ €1,990/month under the 4% rule. Enter your own numbers below.
The calculator compounds your savings monthly at net return = expected return minus fees, growing both your existing pot and every future contribution. It then translates the result into the two numbers that actually matter:
The 25x rule is the same idea in reverse: you need roughly 25 times the annual spending your portfolio must cover. Portfolio-covered spending = total spending minus state pension — a step many European savers skip, even though AOW, the gesetzliche Rente or the French state pension can cover a third or more of the target.
Lukas, 30, in Germany, has €5,000 saved, invests €400/month until 67, expects 6% return with 0.5% fees, 2% inflation, and a €12,000/year state pension:
The fee line is the quiet lesson: at 1% fees instead of 0.5%, the same plan would end up roughly €90,000 smaller. Fees are the one variable you control completely.
A practical starting point is 25 times your annual spending minus your state pension. If you spend €36,000 a year and expect €14,000 from a state pension, your portfolio must cover €22,000 — so your target is about €550,000. The 25x rule assumes a 4% annual withdrawal sustained over ~30 years of retirement.
The 4% rule comes from the 1994 Trinity Study: withdraw 4% of your portfolio in year one, then adjust for inflation each year, and historically the money survives at least 30 years in almost every market scenario tested. For European investors using world-equity ETFs it holds reasonably well, though many researchers now suggest 3.5% for retirements longer than 35 years.
Subtract your expected annual state pension from your spending target before applying the 25x rule. Every European system differs — AOW in the Netherlands, the gesetzliche Rente in Germany, the state pension in France — so check your projected entitlement on your national pension portal and enter it in the calculator's state-pension field.
For a globally diversified equity-heavy portfolio, 6% nominal (about 4% after 2% inflation) is a defensible long-run planning assumption. Use 5% nominal if you want a safety margin, or a lower figure if your portfolio holds many bonds. Never plan on 8–10% — that is the historical average of equities, not a prudent retirement assumption.
At 2% annual inflation — the ECB's long-run target — €1,000 today buys about €820 worth of goods in 10 years and about €670 in 20 years. That is why the calculator shows both the nominal pot and its real value in today's money: the nominal figure always looks impressive, but only the real figure tells you what you can actually buy.
A lot more than the percentage suggests. Over a 35-year career, a 1% annual fee instead of 0.2% can erase roughly a quarter of your final pot — on a €500,000 pot, that is well over €100,000 lost to fees. The calculator's fee field lets you see the damage directly, which is why low-cost index funds dominate European retirement saving.
As early as you can, because compounding rewards time more than amount. Starting at 25 instead of 35 with the same monthly contribution roughly doubles the final pot at 65 — the ten extra years contribute more than the money itself. If you are starting late, raising the monthly amount matters far more than chasing higher returns.
Early retirement stretches the 4% rule past the 30-year horizon it was tested on. For a 40-year retirement, planners generally recommend 3–3.5% instead, which means you need 28–33x your annual spending rather than 25x. Alternatively, plan flexible withdrawals — spending a little less in bad market years dramatically improves survival odds.