Coast FIRE Calculator
You can stop adding to retirement savings once your invested balance can grow to your FIRE number by your target retirement age. For $40,000 a year at a 4% withdrawal rate, a 30-year-old needs $245,234 invested now to coast to 65, assuming 7% returns before 0.3% fees and 2.5% inflation (worked example below).
Coast FIRE calculator
Your FIRE number is $1,000,000. To coast from age 30 you need $245,234 invested now (today's dollars); you have $50,000 — $195,234 short. Saving $12,000 a year, you reach Coast FIRE at age 58 (in 28 years). If you stop saving today, growth alone gets you to about $203,887 by 65.
All amounts are in today's dollars. Coasting means stopping retirement contributions while covering current bills from other income. Constant-return arithmetic, not a retirement recommendation.
Invested balance and Coast FIRE target by age
Ages label year ends. Contributions stop after the first Coast FIRE age; growth continues through retirement. If the target is never reached before retirement, contributions continue through the retirement year. Reaching FI only at retirement does not count as coasting.
| Age at year end | Opening | Growth | Saved | Closing | Coast target |
|---|---|---|---|---|---|
| 31 | $50,000 | $2,049 | $12,000 | $64,049 | $255,283 |
| 32 | $64,049 | $2,624 | $12,000 | $78,673 | $265,743 |
| 33 | $78,673 | $3,224 | $12,000 | $93,897 | $276,632 |
| 34 | $93,897 | $3,847 | $12,000 | $109,744 | $287,967 |
| 35 | $109,744 | $4,497 | $12,000 | $126,241 | $299,767 |
| 36 | $126,241 | $5,173 | $12,000 | $143,414 | $312,050 |
| 37 | $143,414 | $5,876 | $12,000 | $161,291 | $324,836 |
| 38 | $161,291 | $6,609 | $12,000 | $179,899 | $338,147 |
| 39 | $179,899 | $7,371 | $12,000 | $199,271 | $352,002 |
| 40 | $199,271 | $8,165 | $12,000 | $219,436 | $366,426 |
| 41 | $219,436 | $8,992 | $12,000 | $240,428 | $381,440 |
| 42 | $240,428 | $9,852 | $12,000 | $262,279 | $397,070 |
| 43 | $262,279 | $10,747 | $12,000 | $285,027 | $413,340 |
| 44 | $285,027 | $11,679 | $12,000 | $308,706 | $430,277 |
| 45 | $308,706 | $12,649 | $12,000 | $333,355 | $447,908 |
| 46 | $333,355 | $13,659 | $12,000 | $359,014 | $466,261 |
| 47 | $359,014 | $14,711 | $12,000 | $385,725 | $485,367 |
| 48 | $385,725 | $15,805 | $12,000 | $413,531 | $505,255 |
| 49 | $413,531 | $16,945 | $12,000 | $442,475 | $525,958 |
| 50 | $442,475 | $18,131 | $12,000 | $472,606 | $547,510 |
| 51 | $472,606 | $19,365 | $12,000 | $503,971 | $569,944 |
| 52 | $503,971 | $20,651 | $12,000 | $536,622 | $593,298 |
| 53 | $536,622 | $21,988 | $12,000 | $570,610 | $617,609 |
| 54 | $570,610 | $23,381 | $12,000 | $605,991 | $642,916 |
| 55 | $605,991 | $24,831 | $12,000 | $642,822 | $669,259 |
| 56 | $642,822 | $26,340 | $12,000 | $681,162 | $696,683 |
| 57 | $681,162 | $27,911 | $12,000 | $721,073 | $725,230 |
| 58 | $721,073 | $29,546 | $12,000 | $762,620 | $754,946 |
| 59 | $762,620 | $31,249 | $0 | $793,869 | $785,881 |
| 60 | $793,869 | $32,529 | $0 | $826,398 | $818,083 |
| 61 | $826,398 | $33,862 | $0 | $860,260 | $851,604 |
| 62 | $860,260 | $35,250 | $0 | $895,510 | $886,499 |
| 63 | $895,510 | $36,694 | $0 | $932,204 | $922,824 |
| 64 | $932,204 | $38,198 | $0 | $970,401 | $960,637 |
| 65 | $970,401 | $39,763 | $0 | $1,010,164 | $1,000,000 |
Compare Coast FIRE numbers and saving timelines
A later retirement gives the same investments more time to grow when real returns are positive. A later starting age leaves fewer compounding years. Compare those effects before changing your contribution plan; the tables isolate age, return and yearly saving rather than mixing them together.
Coast FIRE number by current age and retirement age ($1,000,000 FIRE number)
| Current age | Retire at 55 | Retire at 60 | Retire at 65 | Retire at 67 |
|---|---|---|---|---|
| 25 | $299,767 | $245,234 | $200,622 | $185,138 |
| 30 | $366,426 | $299,767 | $245,234 | $226,308 |
| 35 | $447,908 | $366,426 | $299,767 | $276,632 |
| 40 | $547,510 | $447,908 | $366,426 | $338,147 |
| 45 | $669,259 | $547,510 | $447,908 | $413,340 |
| 50 | $818,083 | $669,259 | $547,510 | $505,255 |
| 55 | — | $818,083 | $669,259 | $617,609 |
Coast FIRE number per $10,000 of yearly retirement spending (4% withdrawal rate, coasting from 35 to 65)
| Return before fees | Coast number | Multiple of yearly spending |
|---|---|---|
| 4% | $176,317 | 17.63× |
| 5% | $132,207 | 13.22× |
| 6% | $99,405 | 9.94× |
| 7% | $74,942 | 7.49× |
| 8% | $56,648 | 5.66× |
Table 2 is constant-return arithmetic, not a safe-withdrawal study. Multiply its dollar requirement by your annual retirement spending divided by $10,000. The withdrawal rate stays fixed; changing the accumulation return does not establish which withdrawal rate is sustainable.
Age you reach Coast FIRE by yearly saving
| Yearly saving | Coast FIRE age |
|---|---|
| $0 | Not before 65 |
| $6,000 | Not before 65 |
| $12,000 | 58 |
| $18,000 | 45 |
| $24,000 | 41 |
Calculated 2026-11-14 with the model described in /methodology (section 1h).
How to calculate your Coast FIRE number
First calculate FIRE number = yearly retirement spending ÷ withdrawal rate. Then calculate Coast FIRE number = FIRE number ÷ G^(retirement age − current age), where G = (1 + return − fees) ÷ (1 + inflation). Rates in the formulas are decimals. The result is the balance required now, without any future contributions.
In the worked example, $40,000 ÷ 0.04 = $1,000,000. The real growth factor is 1.067 ÷ 1.025, approximately 1.04098. Dividing $1,000,000 by that factor raised to 35 years gives $245,234. Subtracting the existing $50,000 leaves a $195,234 gap today. That gap is a current balance shortfall, not the total future contributions required.
How this calculator works
How to use the calculator
Enter your ages, retirement budget and invested retirement savings. Exclude money you expect to spend before retirement. Add the annual amount you can invest until coasting, then choose the withdrawal rate, return, fees and inflation. Read the stop-today projection separately from the saving-until-coast result. Download the yearly CSV to review contributions, balances and assumptions.
Formulas and timing
Each year applies growth to the opening balance, then adds the contribution at year end. The first whole age before retirement with balance at least equal to that age's coast target is the Coast FIRE age. Contributions stop after that milestone. An already-funded target returns your current age and zero years; otherwise an unreached target says so explicitly.
All amounts retain today's purchasing power, including annual savings. At zero real growth, G equals one and the coast target equals the FIRE number. Negative real growth is allowed: the coast requirement exceeds the FIRE number because purchasing power shrinks. The model does not round balances before comparing them; displayed dollars are rounded.
Common mistakes to avoid
Enter the return as a nominal return before fees, such as 7%, not a real return that already subtracts inflation; the calculator removes inflation itself, so a real-return input counts inflation twice. Enter retirement spending in today's dollars rather than a future inflated budget. Count only invested retirement savings, not cash you plan to spend before retirement.
Coast FIRE vs FIRE, Lean FIRE and Barista FIRE
FIRE means financial independence, retire early: a portfolio target intended to support retirement spending. Coast FIRE reaches an earlier milestone where future growth could complete that target, while work or other income still pays current bills. Lean FIRE uses a smaller spending budget. Barista FIRE combines part-time work with savings or investment withdrawals to cover current expenses; some people earn enough to leave the portfolio untouched. This calculator models only that no-withdrawal coasting case; it does not model part-time income, benefits or withdrawals.
Limits of this calculator
Returns, fees and inflation stay constant. This is not a backtest, simulation or probability of success. Actual losses near retirement can change the outcome even if a long-run average looks adequate; see sequence of returns risk. Reaching the target does not test retirement withdrawals or guarantee lifetime funding.
Taxes and Social Security are not modelled. Social Security lowers the spending the portfolio must cover once benefits begin; review your own estimates at my Social Security and account for timing separately. The calculator also omits account access restrictions, changing household costs and unexpected withdrawals. Revisit the inputs when your budget or retirement date changes.
Coast FIRE calculator FAQ
What is my Coast FIRE number?
It is the invested balance you need today so that assumed growth alone reaches your FIRE number at your chosen retirement age. Divide yearly retirement spending by the withdrawal rate, then discount that target by the real growth factor for the years remaining. It depends on your budget, time and growth assumptions, not your salary.
How much do I need to coast FIRE at 30?
For a $1,000,000 FIRE number at 65, Table 1 gives $245,234 at age 30, using a 7% return before 0.3% fees and 2.5% inflation. Retiring at 55 instead raises that age-30 requirement to $366,426. These are computed thresholds in today’s dollars, not universal savings recommendations.
Is 7% a realistic return for Coast FIRE?
Here 7% is an input, not a forecast or promised return. Table 2 changes the coast requirement per $10,000 of yearly spending from $176,317 at a 4% return to $56,648 at 8%, with fees and inflation fixed. Test lower assumptions and check whether your plan still works instead of relying on one optimistic number.
Can I stop contributing to my 401(k) once I reach Coast FIRE?
The arithmetic says additional contributions are unnecessary for the entered target if every assumption holds. It does not decide whether stopping is appropriate. If your employer offers a contribution-dependent match, stopping may leave employer money on the table. Plan terms, vesting, access rules and taxes need separate review; this calculator gives no tax advice.
What is the difference between Coast FIRE and Barista FIRE?
Coast FIRE means an existing portfolio can grow to the retirement target without more contributions. Barista FIRE combines part-time work with savings or investment withdrawals to cover current expenses; some people earn enough to leave the portfolio untouched. This calculator models only that no-withdrawal coasting case, with annual saving set to zero; it does not model part-time income, benefits or withdrawals.
Does Coast FIRE include inflation?
Yes. This calculator divides the nominal growth factor after fees by one plus inflation. Spending, balances and contributions are all in today’s dollars. A constant yearly saving input therefore assumes nominal contributions increase with inflation. Do not enter a future inflated spending budget as well, because that would count inflation twice.
Source on employer matches: IRS retirement plan contributions.
Related tools
Keep contributing toward full financial independence with the FIRE calculator. Model a gap before benefits with the early retirement calculator. Estimate a withdrawal-horizon target with how much do I need to retire, or check the formulas in methodology.