1. Enter sustainable spending
Use expected monthly expenses in today’s dollars and include irregular annual costs.
Planning
FIRE and Coast FIRE calculator
Estimate the portfolio needed to cover planned expenses and model how long regular investing may take to reach that target.
Target portfolio
$900,000
Estimated time to goal
24 yr 3 mo
Remaining gap
$800,000
Annual expenses
$36,000
Current monthly passive income
$333
Coast FIRE number today
$201,444
Coast FIRE status
Not reached
Current progress11%
Projected portfolio growth
Month 1: $101,416.67Month 1 · $101,416.67
Month 18: $126,423.51Month 18 · $126,423.51
Month 35: $153,261.97Month 35 · $153,261.97
Month 52: $182,066.19Month 52 · $182,066.19
Month 69: $212,980.16Month 69 · $212,980.16
Month 86: $246,158.40Month 86 · $246,158.40
Month 103: $281,766.76Month 103 · $281,766.76
Month 120: $319,983.23Month 120 · $319,983.23
Month 137: $360,998.84Month 137 · $360,998.84
Month 154: $405,018.62Month 154 · $405,018.62
Month 171: $452,262.59Month 171 · $452,262.59
Month 188: $502,966.92Month 188 · $502,966.92
Month 205: $557,385.06Month 205 · $557,385.06
Month 222: $615,789.02Month 222 · $615,789.02
Month 239: $678,470.74Month 239 · $678,470.74
Month 256: $745,743.54Month 256 · $745,743.54
Month 273: $817,943.69Month 273 · $817,943.69
Month 290: $895,432.10Month 290 · $895,432.10
Month 291: $900,163.07Month 291 · $900,163.07
Month 1Month 291
Hover, tap or focus a column to see its exact value.
Monthly FIRE projection
Detailed values use the same assumptions as the summary above.
| Month | Starting portfolio | Contribution | Return for month | Ending portfolio |
|---|---|---|---|---|
| 1 | $100,000.00 | $1,000.00 | $416.67 | $101,416.67 |
| 2 | $101,416.67 | $1,000.00 | $422.57 | $102,839.24 |
| 3 | $102,839.24 | $1,000.00 | $428.50 | $104,267.73 |
| 4 | $104,267.73 | $1,000.00 | $434.45 | $105,702.18 |
| 5 | $105,702.18 | $1,000.00 | $440.43 | $107,142.61 |
| 6 | $107,142.61 | $1,000.00 | $446.43 | $108,589.04 |
| 7 | $108,589.04 | $1,000.00 | $452.45 | $110,041.49 |
| 8 | $110,041.49 | $1,000.00 | $458.51 | $111,500.00 |
| 9 | $111,500.00 | $1,000.00 | $464.58 | $112,964.58 |
| 10 | $112,964.58 | $1,000.00 | $470.69 | $114,435.26 |
| 11 | $114,435.26 | $1,000.00 | $476.81 | $115,912.08 |
| 12 | $115,912.08 | $1,000.00 | $482.97 | $117,395.05 |
Withdrawal rates and investment returns are uncertain. This scenario is not retirement advice.
Calculation method
How the financial independence target is calculated
Annual expenses are divided by the selected withdrawal rate. The time estimate then grows the current portfolio monthly at the real return and adds the planned monthly investment.
Detailed guide
FIRE target, passive income and Coast FIRE
A financial-independence target estimates the portfolio needed to support annual spending at a selected withdrawal rate. The calculator also projects time to the target from current assets, monthly investing and a real return after inflation.
Coast FIRE is the amount needed today that could grow to the target by retirement without further contributions. Current passive income shows the monthly amount implied by applying the chosen withdrawal rate to today’s portfolio.
Build a FIRE scenario
2. Set return and withdrawal assumptions
Use a real return after inflation and test more than one withdrawal rate.
3. Add ages for Coast FIRE
Current and retirement ages determine how long today’s investments can compound without new contributions.
FIRE and Coast FIRE formulas
FIRE target = Annual expenses ÷ Withdrawal rate
The Coast FIRE number discounts the target back from retirement at the selected real return.
Time to full FIRE is simulated monthly by growing the current portfolio and adding the planned contribution until the target is reached.
FIRE example
Monthly spending of $3,000 is $36,000 per year. At a 4% withdrawal rate, the target is $900,000. A lower withdrawal rate increases the required portfolio.
Important planning assumptions
Withdrawal risk
A withdrawal rate is not guaranteed. Retirement length, asset allocation, taxes and the sequence of market returns all matter.
Real return
Use a return after inflation so spending and the target remain in today’s purchasing power.
Coast FIRE meaning
Reaching Coast FIRE means the modeled current portfolio can grow to the target without new deposits; it does not mean current expenses are funded today.
Decision guide
Build a financial-independence range, not a promise
Leading Coast FIRE and retirement pages discuss spending, withdrawal rates, inflation, and the difference between accumulation and drawdown. The calculator connects assumptions; it cannot guarantee that a portfolio will earn a steady return in every year.
Start with spending
Estimate annual spending in today’s dollars and identify costs that may change after work becomes optional. Housing, health care, taxes, and irregular large purchases deserve separate lines. A credible spending estimate is more useful than choosing an attractive round-number portfolio target.
Treat the withdrawal rate as a scenario
A target derived from spending divided by a withdrawal rate depends on horizon, asset mix, inflation, and market sequence. Test several rates. A long retirement or less flexible spending generally needs more margin than a short projection suggests.
Separate accumulation and withdrawals
Before the target date, contributions add to the portfolio; afterward, withdrawals reverse the cash flow. Poor returns near the beginning of withdrawals can be especially damaging. Keep a liquid reserve and test a delayed date, lower return, and partial earned-income case.
Basic FIRE stress test
- Use a complete annual budget.
- Test several withdrawal rates.
- Include inflation, fees, and taxes.
- Model weak early returns.
How to compare scenarios
Save a baseline, then change only one input at a time: amount, rate, term, or recurring payment. Record the supporting outputs as well as the headline result—contributions, interest, total cost, remaining balance, or target date. This isolates the assumption that actually changes the decision instead of hiding it inside several simultaneous edits.
Do not tune every assumption until the calculator produces a preferred answer. Start with a cautious case, follow with a central case, and treat the favorable case as an upside scenario. A calculator result is not a lender quote, market forecast, or tax determination; actual dates, rounding, fees, contract rules, and required payments must be checked in primary documents.
Keep enough precision in the inputs and round only the output used for a decision. If the estimate supports a transaction, loan, tax calculation, or long-term plan, repeat it with figures from the contract or official statement. Any difference helps identify the assumption that still needs verification.
FIRE and Coast FIRE questions
What does the 4% rule mean?
It is a historical planning reference that starts withdrawals near 4% of a portfolio, not a guarantee for every market or retirement.
What is Coast FIRE?
It is the present portfolio that could reach the future FIRE target through growth alone by the selected retirement age.
Why use real return?
A real return keeps future portfolio values and expenses on the same inflation-adjusted basis.
Does the result include Social Security or a pension?
Not directly. Reduce the expenses the portfolio must cover when reliable outside income is expected.
Updated: July 28, 2026
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