How Much Do You Need to Retire at 50?

The 4% rule (and its inverse, the 25× rule) was originally back-tested by William Bengen and the Trinity Study on a 30-year retirement. Retire at 50 and you may need the money to last 40–45 years — long enough that historically safe withdrawal rates drop to around 3.0–3.5%.

In practice that means using 28× to 33× annual expenses as your target instead of the textbook 25×. On €30,000/yr of spending that's €840,000–€990,000 rather than €750,000. Model this in the calculator above by either raising monthly expenses by ~15–20% or, equivalently, dragging the target nest-egg field up directly.

If you retire at 50 in the United States, Medicare is 15 years away. Unsubsidized ACA premiums for a 50-year-old typically run $800–$1,500/month, climbing each year — and a couple can easily face $20,000–$30,000/year in combined premiums plus out-of-pocket costs.

In Europe the equivalent is voluntary private cover or topping up state cover after losing employer-linked benefits. Realistic budgets: €400–€800/month per adult in Germany (PKV), €100–€300/month in France (mutuelle), £200–£400/month in the UK for private cover. Add this number to the calculator's monthly-expenses field — it's the single biggest line item most people miss.

401(k) and traditional IRA withdrawals before 59½ trigger a 10% penalty on top of income tax. At 50 you've got nearly a decade to bridge. Three practical levers:

• Rule 72(t) / SEPP: Substantially Equal Periodic Payments let you draw a fixed actuarial amount from an IRA penalty-free, but you must continue for 5 years or until 59½ — whichever is longer. Mess up the schedule and the IRS retroactively applies all penalties.
• Roth conversion ladder: Convert a year of expenses from traditional to Roth every year. After a 5-year season each converted amount can be withdrawn penalty-free. Start the ladder the year you retire so the first rungs are ready at 55.
• Taxable brokerage bridge: The simplest path. Build a 5–10 year expense buffer in a taxable account; long-term capital gains at 0% or 15% are usually cheaper than the penalty.

Two retirees can have identical average returns over 40 years and end up with wildly different outcomes — the one who hit a bad market in years 1–5 can run out of money decades earlier. This is sequence-of-returns risk, and it's the single biggest danger of retiring at 50.

Standard mitigations: hold 2–3 years of expenses in cash or a very low-risk account (or low-volatility ETFs), glide your equity ETF exposure down around the retirement date (say 50–60% in lower-volatility / dividend ETFs at 50, easing back to 70–80% equity ETFs by 65), and pre-commit to spending cuts of 5–10% in any year your portfolio drops more than 20%.

At a 7% real return, the math is unforgiving. Starting from €0 at 30 and retiring at 50 (20 years of compounding) requires saving roughly 55–65% of gross income to hit a €750K target. Start at 25 (25 years) and that drops to about 40–45%. Start at 35 and it's closer to 80% — usually only feasible with a partner or a high-income year on top.

Use the calculator above to back-solve your exact number. Adjust current age, current savings and target — the 'Save €X/mo' figure is the answer for your numbers.

Coast FIRE is the point where your existing portfolio, growing at the assumed real return without any new contributions, hits your nest-egg target by your chosen retirement age. To coast to €750K by 50 at 7% real, you'd need roughly €280K invested by 30, €390K by 35, or €545K by 40.

After you cross that line you can drop to a lower-paying job, take a sabbatical, or shift to part-time work — as long as you can cover current expenses from earned income, the retirement portfolio takes care of itself.