№ 030 · Retirement cluster
Retirement & FIRE Calculator
Two numbers decide when you’re free: how much you need, and how long it takes to get there. Set your annual expenses to find your FIRE number with the 4% rule, then watch your savings climb toward it — and see the year you could walk away.
The 4% rule
Want to project a portfolio in nominal vs today’s dollars? See the Investment Growth Calculator, the raw mechanics in the Compound Interest Calculator, or capture your employer match in the 401(k) Calculator. Wondering if you can stop saving already? Check your Coast FIRE number, compare bare-bones to comfortable in the Lean vs Fat FIRE Calculator, or — once you’re there — see how long it lasts with the Retirement Withdrawal Calculator.
Your target01
$
%
Where you stand02
$
$
yr
Growth03
%
Financial independence in 17 years 8 mo · age 52
$1,000,000.00
your FIRE number · safe to withdraw ≈ $40,000.00/yr
≈ $1,005,334.88 at FI$474,000.00 contributed
FIRE number$1,000,000.00
Safe withdrawal / yr$40,000.00
Total contributed$474,000.00
Portfolio at FI$1,005,334.88
- Balance$1,005,334.88
- Contributed$474,000.00
- FIRE number$1,000,000.00
| Year 1 | balance $78,399.67, contributed $74,000.00 |
|---|---|
| Year 2 | balance $108,852.36, contributed $98,000.00 |
| Year 3 | balance $141,506.48, contributed $122,000.00 |
| Year 4 | balance $176,521.17, contributed $146,000.00 |
| Year 5 | balance $214,067.07, contributed $170,000.00 |
| Year 6 | balance $254,327.16, contributed $194,000.00 |
| Year 7 | balance $297,497.66, contributed $218,000.00 |
| Year 8 | balance $343,788.96, contributed $242,000.00 |
| Year 9 | balance $393,426.67, contributed $266,000.00 |
| Year 10 | balance $446,652.68, contributed $290,000.00 |
| Year 11 | balance $503,726.41, contributed $314,000.00 |
| Year 12 | balance $564,926.01, contributed $338,000.00 |
| Year 13 | balance $630,549.72, contributed $362,000.00 |
| Year 14 | balance $700,917.38, contributed $386,000.00 |
| Year 15 | balance $776,371.93, contributed $410,000.00 |
| Year 16 | balance $857,281.09, contributed $434,000.00 |
| Year 17 | balance $944,039.18, contributed $458,000.00 |
| Year 18 | balance $1,005,334.88, contributed $474,000.00 |
Year by year
| Year | Contributed | Balance | Gap to FIRE |
|---|---|---|---|
| 1 | $74,000.00 | $78,399.67 | $921,600.33 |
| 2 | $98,000.00 | $108,852.36 | $891,147.64 |
| 3 | $122,000.00 | $141,506.48 | $858,493.52 |
| 4 | $146,000.00 | $176,521.17 | $823,478.83 |
| 5 | $170,000.00 | $214,067.07 | $785,932.93 |
| 6 | $194,000.00 | $254,327.16 | $745,672.84 |
| 7 | $218,000.00 | $297,497.66 | $702,502.34 |
| 8 | $242,000.00 | $343,788.96 | $656,211.04 |
| 9 | $266,000.00 | $393,426.67 | $606,573.33 |
| 10 | $290,000.00 | $446,652.68 | $553,347.32 |
| 11 | $314,000.00 | $503,726.41 | $496,273.59 |
| 12 | $338,000.00 | $564,926.01 | $435,073.99 |
| 13 | $362,000.00 | $630,549.72 | $369,450.28 |
| 14 | $386,000.00 | $700,917.38 | $299,082.62 |
| 15 | $410,000.00 | $776,371.93 | $223,628.07 |
| 16 | $434,000.00 | $857,281.09 | $142,718.91 |
| 17 | $458,000.00 | $944,039.18 | $55,960.82 |
| 18 | $474,000.00 | $1,005,334.88 | $0.00 |
How it works · methodology
The math, in the open.
FIRE number = annual expenses ÷ (withdrawal rate ÷ 100) (at 4% → 25 × expenses) each month: balance = balance × (1 + real return ÷ 12) + contribution years to FI = the first month the balance reaches your FIRE number
- expenses
- Annual spending in retirement (today’s dollars)
- WR
- Safe withdrawal rate (4% rule)
- r
- Expected real (after-inflation) return
- PMT
- Monthly contribution
Assumptions & limits
- The 4% rule (Bengen / Trinity study): a diversified portfolio has historically sustained ~4% inflation-adjusted withdrawals for about 30 years.
- Returns are real (after inflation) and held constant; real markets vary year to year.
- No taxes, fees, Social Security, pensions, or sequence-of-returns risk are modeled.
- A planning estimate, not a guarantee or financial advice.
By the MintNumber Editorial Team·Reviewed
Frequently asked
Questions about FIRE
What is the 4% rule, and the 25× rule?
The 4% rule (from the Trinity study and William Bengen’s research) says a diversified portfolio can sustain withdrawals of about 4% of its starting value in year one, rising with inflation, for ~30 years with high historical success. Flip it around and your target — your FIRE number — is 25× your annual expenses (because 1 ÷ 4% = 25).
What’s my FIRE number?
Your annual retirement expenses divided by your safe withdrawal rate. At 4%, that’s 25× expenses; spend $40,000/yr and you need $1,000,000. A more conservative 3.5% rate raises it to ~28.6× ($1,142,857), and a more aggressive 5% lowers it to 20× ($800,000). Lower rate = bigger cushion.
Why does this use a real (after-inflation) return?
So everything is in today’s dollars. Your FIRE number is built from today’s expenses, so we grow your portfolio at a real return and compare like with like — no separate inflation term and no double-counting. Enter roughly 7% (a long-run ~10% nominal minus ~3% inflation), not 10%.
What return should I use?
A broad U.S. stock portfolio has returned roughly 7% per year after inflation over the long run, but any decade can be very different, and the order of returns matters a lot near retirement (sequence-of-returns risk). Use a conservative figure and treat the result as a planning estimate, not a guarantee.
What about Coast, Lean, and Fat FIRE?
They’re variations on the same idea. Coast FIRE is having enough invested that it will grow to your number by retirement age without any more contributions. Lean and Fat FIRE just use lower or higher annual spending (a smaller or larger FIRE number) — compare all three side by side in the dedicated Lean vs Fat FIRE calculator.