FIRE charts
Wealth projection, Monte Carlo and success rate.
The FIRE calculator produces four charts and a statistics card for assessing how solid a plan is. Each answers a different question, and the order you read them in matters.
Portfolio projection
An area chart with confidence bands (25th–75th percentile) showing the median portfolio value at each age, from accumulation through to estimated death.
It includes reference lines for FIRE age, pension start, extraordinary expenses and long-term care, plus amber markers for unexpected events.
How to read it: the median line is the central scenario, not "what will happen". The width of the band is the real information. If at age 80 the band runs from €200,000 to €3 million, the plan isn't "about a million": it's a plan whose outcome depends decisively on which markets you happen to get.
Probability of success
A line chart with the percentage of simulations in which the portfolio survives to each age.
Above 80% a plan is generally considered robust. But look at the shape of the curve too: a steep drop over a narrow range signals a fragile plan concentrated on a few critical years; a gentle decline indicates a plan that degrades gradually and is easier to correct along the way.
Failure age distribution
A histogram showing at what age the portfolio runs out in unsuccessful simulations. If every simulation succeeds, a confirmation message replaces the chart.
This is the most useful chart for understanding where the risk sits. If failures cluster in the first years after FIRE, the problem is sequence risk: a bad market right after you stop working, while you're withdrawing. The countermeasures differ from those for a plan that fails at 90: the first calls for a buffer or early flexibility, the second for more capital or less spending.
Inheritance distribution
A histogram of remaining wealth at death across simulations, in two views: nominal (current euro) and real (inflation-adjusted). The median value is also shown.
Always judge on the real view. A nominal €800,000 inheritance forty years out is not €800,000 today, and the gap between the two views is the most concrete measure of how much inflation matters over these horizons.
A very high median also says something about you: if the plan systematically leaves substantial wealth behind, you're funding your heirs with years of your own time. That might be a deliberate choice, or a sign you could stop earlier.
Statistics card
A summary panel with four key metrics:
| Metric | What it says |
|---|---|
| Probability of success % | Share of simulations in which capital lasted |
| Median survival age | How long the portfolio holds in the central case |
| Median inheritance (€) | What's left at death in the median scenario |
| Worst case | The earliest failure age observed |
The card also reports the simulation parameters used: handy for comparing two scenarios without relying on memory about what you'd set.
The levers that actually move the result
When the probability doesn't satisfy you, the levers don't all weigh the same. In rough order of impact:
- Postponing FIRE by 1–2 years: it works twice: it adds contributions and shortens the withdrawal phase.
- Reducing post-FIRE spending: permanently lowers the capital required.
- Increasing contributions: effective, but with diminishing returns close to FIRE.
- Changing allocation: the least predictable: more equity raises the median and widens the band, and on sequence risk it can make things worse.