FIRE Calculator
Financial Independence, Retire Early: find the portfolio size that could cover your spending forever, and how long it takes to get there.
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The classic '4% rule' is the common starting point
Long-term diversified portfolios have averaged about 7% after inflation
Your path to FIRE
At a 4% withdrawal rate
Your FIRE number
$1,250,000
$50,000/year ÷ 4% withdrawal rate
Time to reach it
21 yr 1 mo
Progress today
8%
Portfolio growth toward your FIRE number
Starting at $100,000 with $1,500/month at 7% returns
How the FIRE number works
How this FIRE calculator works
$50,000 in annual spending at a 4% withdrawal rate means a $1.25 million FIRE number. Starting with $100,000 saved and investing $1,500 a month at a 7% return gets there in a little under 21 years. The FIRE number itself is just your annual spending divided by a safe withdrawal rate.
At the classic 4% rule, that works out to 25 times your yearly expenses: a portfolio large enough that withdrawing 4% a year has historically survived most 30-year retirements. Read more in our FIRE movement guide.
Why spending drives the number more than income
Notice that spending, not income, sets the target. Cutting annual expenses lowers the goal and frees up more money to save at the same time, which is why the FIRE timeline is so sensitive to spending in particular. Someone earning $150,000 who spends $120,000 of it needs a much bigger portfolio than someone earning $70,000 who spends $40,000, even though the second person makes less.
This is also why lifestyle creep is the real enemy of an early retirement plan. A raise that gets fully absorbed into higher spending raises the FIRE number right along with it, which cancels out the extra income entirely.
What the 4% rule does and does not cover
The 4% rule comes from historical market returns over rolling 30-year periods, and it held up in most of them. It does not account for a market crash that happens to hit in your first few years of retirement, which is the scenario that actually breaks a withdrawal plan, since pulling money out of a shrunken portfolio locks in losses that a lump sum sitting untouched would eventually recover from. Some people target a lower withdrawal rate, like 3.5%, specifically to build in room for a bad sequence of returns early on.
How this is calculated
It sizes the portfolio that could fund your spending indefinitely, then simulates saving toward it.
FIRE number = annual spending ÷ withdrawal rate (25× spending at the 4% rule). Your current savings and monthly contributions are then grown month by month at your expected return until the balance crosses that line.
What it assumes
- Returns are a steady average. Real sequences of returns matter a lot in early retirement.
- Spending stays constant in today's dollars; use an inflation-adjusted (real) return.
- No taxes on growth or withdrawals are modeled.
Frequently asked questions
What is the 4% rule?
A guideline suggesting a portfolio can support withdrawing 4% of its value in the first year of retirement, adjusted for inflation thereafter, based on historical data showing that rate held up over most 30-year periods. It's a reference point, not a guarantee.
What's the difference between FIRE and normal retirement planning?
FIRE (financial independence, retire early) applies the same withdrawal-rate math decades earlier than a traditional retirement age, which requires a much higher savings rate during the working years to reach the number sooner.
Is a 4% withdrawal rate too aggressive for an early retirement?
Some FIRE planners use a more conservative 3-3.5% for very early retirements, since a longer retirement horizon gives market downturns more time to do damage to a portfolio. Try a lower rate in this calculator to see how much more it requires saved.
Uses a constant return and withdrawal rate; real markets vary and early retirements can outlive the 4% rule's assumptions. For educational purposes only, not financial advice.