FIRE Calculator
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Find out how much you need to be financially independent and roughly how many years it will take at your current savings pace. Enter your savings, income, expenses, expected return and safe withdrawal rate to see your FI number and timeline.
What FIRE means
FIRE stands for Financial Independence, Retire Early. The idea is to save and invest aggressively enough that the returns on your portfolio can cover your living costs indefinitely, giving you the option to stop working long before a traditional retirement age. Financial independence is the milestone; retiring early is just one thing you can choose to do once you reach it.
This calculator answers the two questions at the heart of FIRE: how big does my portfolio need to be, and how long until I get there at my current pace?
Your FI number and the 4% rule
Your FI number is the portfolio size that can fund your spending from investment returns alone. It comes straight from your safe withdrawal rate — the percentage of the portfolio you plan to draw each year. The lower the withdrawal rate, the larger the portfolio you need, but the safer it is against running out.
The 4% rule, drawn from historical market studies, suggests withdrawing 4% of your starting portfolio each year is likely to last decades. That is why 4% is the default here, and why financial independence is often shorthanded as '25 times annual expenses'.
- FI number = annual expenses ÷ (safe withdrawal rate ÷ 100)
- At 4% that equals annual expenses × 25
- At 3% (more conservative) it equals annual expenses × 33.3
- Lower spending shrinks the FI number as much as higher income raises savings
How the timeline is projected
To estimate years to FI, the tool simulates your finances forward one year at a time. Each year it grows your existing balance by the expected return, then adds your annual surplus — income minus expenses. It counts the years until the balance reaches your FI number.
This shows why the savings rate matters so much: the surplus you add every year is the engine early on, while compounding returns take over as the balance grows. Cutting expenses is doubly powerful because it raises your surplus and lowers your FI number at the same time.
Assumptions and limits
The projection assumes a steady return every year and unchanged income and expenses, which real life rarely delivers. Markets are volatile, and the sequence of returns — especially bad years early in retirement — can matter as much as the average. The safe withdrawal rate is a rule of thumb from past data, not a guarantee for the future.
It also works in today's money for the withdrawal-rate logic while compounding nominal savings, and it ignores taxes, healthcare, and one-off costs. Use the result as a directional target and revisit it as your income, spending and markets change.
Small changes to your inputs move the timeline a lot, so try a few scenarios. Trimming annual expenses lowers your FI number and lifts your savings rate together, which is often the fastest lever toward independence.
Frequently asked questions
What is a safe withdrawal rate?
It's the percentage of your portfolio you plan to withdraw each year in retirement. 4% is the common benchmark; more cautious savers use 3–3.5% for a larger safety margin, which raises the FI number they need.
Why do lower expenses matter so much?
Cutting spending works on both sides of the equation: it shrinks your FI number because you need less to cover a smaller lifestyle, and it grows your annual surplus so you save faster. That double effect usually beats chasing a higher return.
Does the calculator account for inflation?
It compounds savings in nominal terms and derives the FI number from today's expenses. For a rough real-terms view, use an inflation-adjusted (real) return figure rather than a nominal one.
What if my income doesn't exceed my expenses?
If you have no annual surplus and no investment growth, the balance can't rise toward the target, so the tool reports that FI isn't reachable at that pace. Increasing income, cutting expenses, or earning a return changes that.
Is the 4% rule guaranteed to work?
No. It's based on historical U.S. market data over 30-year retirements and can fail in unusually bad conditions or over longer horizons. Treat it as a planning guideline and keep flexibility in your spending.
Does reaching my FI number mean I have to retire?
Not at all. It means work becomes optional. Many people who reach financial independence keep working on their own terms, cut back to part-time, or switch to lower-paid work they enjoy.
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