FIRE Calculator
The portfolio that would cover your spending indefinitely, the age you reach it, and the coast point that arrives long before either.
The address carries whatever you changed, so anyone opening it sees these numbers. Nothing is saved on our side.
Financially independent in
14 years 6 months
At age 46.5. Saving 50% of income gets you to $1,625,000, which supports $65,000 a year at a 4% withdrawal rate.
- $1,625,000
- spending ÷ 4%
- 50%
- $65,000 a year
- 46.5
- $313,153
- stop saving, retire at 65
- $4,800
- a year, indefinitely
- $622,699
- by age 65
The savings rate is the whole calculation
Income held constant, spending varied. Every point of savings rate lowers the target and raises the contribution at the same time, which is why the effect is so steep.
| Savings rate | Months to get there | Target portfolio | vs yours |
|---|---|---|---|
| Saving 20%At 64 years old | $381 | +$975,000 more in total | |
| Saving 30%At 57 years old | $294 | +$650,000 more in total | |
| Saving 40%At 51 years old | $228 | +$325,000 more in total | |
| Saving 50%yoursAt 47 years old | $174 | — | |
| Saving 60%At 43 years old | $128 | −$325,000 less in total | |
| Saving 70%At 39 years old | $88 | −$650,000 less in total |
This is the observation that makes the arithmetic interesting. A dollar you stop spending is worth far more than a dollar you start earning, because it moves both ends of the equation: it becomes a dollar saved, and it permanently reduces the portfolio that has to fund your life. A raise you spend moves neither.
Coasting, which arrives long before independence
A milestone people pass without noticing, and it is the one that actually changes your options.
Your coast number is $313,153. Reach it and, contributing nothing further, compound growth alone brings the portfolio to $1,625,000 by age 65.
You are $193,153 away. Past that point, an ordinary retirement is handled and further saving is buying time rather than security.
This is worth knowing because it is reachable years earlier than full independence, and it is the point at which a lower-paid job you would rather do stops being a financial risk.
On the withdrawal rate
The familiar 4% figure comes from the Trinity study of 1998, which tested how US portfolios survived 30-year retirements historically. It is a rule of thumb from one dataset over one period, not a law.
A 45-year retirement is a materially different question from a 30-year one, which is why it is an input here rather than a constant. Move the slider and watch the target: the difference between 3% and 4% is a third of your working life.
How this calculator works
Two numbers do most of the work, and one convention keeps them honest.
The target is annual spending divided by the withdrawal rate. The timeline is then a month-by-month projection: the portfolio grows at the real return and the difference between income and spending is added each month, until the balance reaches the target.
The return is treated as real — after inflation — so the target stays in today’s money and means something. Pairing a nominal return with today’s spending would compare future dollars against present costs and overstate how close you are, which is the most common way this calculation goes wrong.
The coast number is the target discounted back to today at the same return: the balance which, contributed to no further, reaches the target by your traditional retirement age on growth alone.
What is assumed
- A constant real return, every year, with no volatility.
- Income and spending flat in real terms until you stop.
- Income entered after tax, so saving and spending compare.
- No tax on withdrawals, no healthcare gap, no Social Security.
A worked example
Age 32, $120,000 invested, $130,000 of after-tax income against $65,000 of spending, 5% real, 4% withdrawal.
| Target portfolio | $65,000 ÷ 4% |
|---|---|
| Saved each year | 130,000 − 65,000 |
| Savings rate | 65,000 ÷ 130,000 |
| Reached in | 174 months |
| At age | 32 + 14.5 |
| Coast number | 1,625,000 discounted 33 years at 5% |
| Already invested | Of that coast number |
The coast number is the figure worth noticing here. At $313,153 — less than a fifth of the full target — this person could stop contributing entirely and still retire at 65 with $1.625m. On a 50% savings rate that milestone arrives roughly four years from now, a decade before independence itself.
Now change one thing. Cut spending to $52,000 and the target falls to $1.3m while the annual saving rises to $78,000 — the date moves forward by years on a $13,000 change, because it moved both numbers at once. A $13,000 raise, spent, would move neither. That asymmetry is the entire insight of the exercise, and it is arithmetic rather than ideology.
Questions people ask
Annual spending divided by your withdrawal rate. At a 4% rate that is 25 times your spending; at 3% it is 33 times. Note it depends on what you spend, not what you earn — two people on the same salary with different spending have completely different targets, and the one who spends less reaches theirs much sooner for two separate reasons.
It is a rule of thumb, not a law, and this calculator treats it as an input for that reason. The figure comes from the Trinity study (Cooley, Hubbard and Walz, 1998), which examined how US portfolios survived 30-year retirements historically. A retirement beginning at 45 might run 45 years, which is a materially different question, and future returns are not obliged to resemble the sample. Move the slider and see what your own assumption implies.
Because spending less moves both ends of the equation at once. A dollar you stop spending becomes a dollar saved, and it also permanently reduces the portfolio needed to fund your life — by 25 dollars at a 4% withdrawal rate. A raise that you spend does neither. This is why the timeline depends so heavily on the savings rate and so little on the absolute income.
The amount that, left alone from today, grows to your target by traditional retirement age without another dollar contributed. Reaching it is a genuine milestone: an ordinary retirement is handled, and everything you save from that point is buying an earlier date rather than security. It arrives years before full independence and changes what career risks you can afford to take.
Real — after inflation — which is what this calculator assumes. Using a nominal return alongside today's spending figures is the most common error in this calculation, and it flatters the answer substantially: it compares tomorrow's dollars against today's costs. Keeping everything in today's money means the target you compute is the target you will actually need.
Quite a lot, deliberately. Tax on withdrawals and the account types that change it, healthcare before Medicare eligibility, Social Security, and sequence-of-returns risk — the fact that a bad decade early in retirement hurts far more than the same decade later. A constant return is a planning tool, not a forecast, and real markets do not deliver the average every year.
Related calculators
A planning tool, not a forecast. It uses a constant real return and takes no account of tax on withdrawals, healthcare costs before Medicare, Social Security, or the fact that the order in which returns arrive changes the outcome.