Coast FIRE Calculator
Find out how much you need invested today so that — without saving another dollar — compounding alone could carry you to financial independence by your target retirement age, all in today's dollars.
What this calculator shows
It finds your Coast FIRE number — the amount that, left to compound with no further contributions, could grow to your FIRE number by the age you want to retire. It also shows whether you've already reached it and, if not, when you would at your current savings rate. Returns and the withdrawal rate are your assumptions, not forecasts or advice.
Inputs
Everything is in today's dollars. Adjust the assumptions and the results update instantly.
Needed to count the years until retirement.
The age you want to be independent by.
What you have invested today.
Added at the end of each month, in today's dollars.
About $3,333 per month.
Nominal; converted to a real rate using inflation.
Keeps everything in today's dollars.
Assumption, not advice (2-6%).
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Results
Your Coast FIRE number and where you stand today, in today's dollars.
Coast FIRE number
$222,281
Amount needed invested today.
Your progress
22.5%
Current portfolio ÷ Coast FIRE number.
Still needed today
$172,281
To reach Coast FIRE right now.
Coast FIRE age
52
Age you could stop saving for retirement.
Years until Coast FIRE
22.4
At your current contribution.
If you coast from today
$224,940
vs FIRE number of $1,000,000.
FIRE number
$1,000,000
Annual expenses ÷ withdrawal rate.
This model assumes steady returns in today's dollars. It does not simulate market crashes, volatility, or the timing risk of withdrawals (sequence-of-returns risk). Real outcomes will differ.
Path to Coast FIRE & retirement
Your projected portfolio with contributions, the dashed "coast from today" curve if you stopped saving now, and your FIRE number — all in today's dollars.
Contributions vs growth
How much of your portfolio is your own money versus compounding growth over the years to retirement.
Insights
What your assumptions mean for coasting — and the trade-offs behind the numbers.
Your Coast FIRE number
To coast to your FIRE number by age 65, you'd need about $222,281 invested today.
Your progress
Your $50,000 is about 22.5% of your Coast FIRE number.
When you could coast
Contributing $1,000/month, you could reach Coast FIRE in about 22.4 years — around age 52. After that you no longer need to save for retirement, only cover your current expenses.
If you stopped today
If you stopped contributing today, your portfolio could grow to about $224,940 by age 65 — below your FIRE number of $1,000,000.
Why it's smaller than FIRE
Coast FIRE ($222,281) is much smaller than your full FIRE number ($1,000,000) because compounding does the rest over 35 years.
Time is the biggest lever
The more years until retirement, the smaller your Coast FIRE number — starting early is what makes coasting possible.
Shown in today's dollars
These results are in today's dollars, so your goal and the projection are directly comparable.
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Try the FIRE CalculatorYear-by-year projection
How your portfolio grows toward the Coast FIRE number needed at each age, in today's dollars.
| Year | Age | Portfolio value | Contributions | Growth | Coast number needed | Coast progress |
|---|---|---|---|---|---|---|
| 1 | 31 | $64,435 | $12,000 | $2,435 | $232,040 | 27.8% |
| 2 | 32 | $79,503 | $24,000 | $5,503 | $242,227 | 32.8% |
| 3 | 33 | $95,233 | $36,000 | $9,233 | $252,862 | 37.7% |
| 4 | 34 | $111,654 | $48,000 | $13,654 | $263,963 | 42.3% |
| 5 | 35 | $128,795 | $60,000 | $18,795 | $275,551 | 46.7% |
| 6 | 36 | $146,689 | $72,000 | $24,689 | $287,649 | 51% |
| 7 | 37 | $165,369 | $84,000 | $31,369 | $300,277 | 55.1% |
| 8 | 38 | $184,868 | $96,000 | $38,868 | $313,460 | 59% |
| 9 | 39 | $205,224 | $108,000 | $47,224 | $327,222 | 62.7% |
| 10 | 40 | $226,474 | $120,000 | $56,474 | $341,588 | 66.3% |
| 11 | 41 | $248,656 | $132,000 | $66,656 | $356,584 | 69.7% |
| 12 | 42 | $271,812 | $144,000 | $77,812 | $372,239 | 73% |
| 13 | 43 | $295,985 | $156,000 | $89,985 | $388,581 | 76.2% |
| 14 | 44 | $321,219 | $168,000 | $103,219 | $405,641 | 79.2% |
| 15 | 45 | $347,561 | $180,000 | $117,561 | $423,450 | 82.1% |
| 16 | 46 | $375,059 | $192,000 | $133,059 | $442,040 | 84.8% |
| 17 | 47 | $403,765 | $204,000 | $149,765 | $461,447 | 87.5% |
| 18 | 48 | $433,731 | $216,000 | $167,731 | $481,705 | 90% |
| 19 | 49 | $465,012 | $228,000 | $187,012 | $502,853 | 92.5% |
| 20 | 50 | $497,667 | $240,000 | $207,667 | $524,930 | 94.8% |
| 21 | 51 | $531,755 | $252,000 | $229,755 | $547,976 | 97% |
| 22 | 52 | $567,340 | $264,000 | $253,340 | $572,033 | 99.2% |
| 23 | 53 | $604,487 | $276,000 | $278,487 | $597,147 | Reached |
| 24 | 54 | $643,265 | $288,000 | $305,265 | $623,363 | Reached |
| 25 | 55 | $683,746 | $300,000 | $333,746 | $650,730 | Reached |
Understanding Coast FIRE
An educational model, not a forecast. It compounds your portfolio monthly at an inflation-adjusted (real) return and keeps everything in today's dollars.
What Coast FIRE is
Coast FIRE is the point where your existing investments will grow to your FIRE number withoutany new contributions. You still work to cover today's expenses — you just no longer need to save for retirement.
Coast FIRE vs. FIRE
FIRE means you could stop working entirely. Coast FIRE is earlier and smaller: it means you could stop saving for retirement. See the FIRE Calculator for the full independence picture.
The Coast FIRE number
It is your FIRE number discounted back by expected real growth over the years to retirement — roughly your FIRE number ÷ (1 + real return) raised to the number of years. This is the same idea as compound interest run in reverse.
Why time is the biggest lever
More years to retirement means more compounding, which means a smaller Coast FIRE number today. Starting early is what makes coasting possible.
Why today's dollars
Using a real (inflation-adjusted) return keeps your future goal comparable to what you spend today. It also assumes your contributions hold their purchasing power over time. Learn more about inflation.
Why returns aren't guaranteed
Markets vary, and the order of returns matters (sequence-of-returns risk). This model assumes a steady real return and does not simulate that risk, taxes, or fees.
What this does not include: taxes, account-type rules, Social Security or pensions, healthcare costs, variable spending, and sequence-of-returns risk. Real outcomes would reflect these.
This is one of several educational models on Rionux. See how we model these projections across all our tools.
Frequently asked questions
What is Coast FIRE?
Coast FIRE is the point where the money you already have invested is enough that, without adding another dollar, compounding alone could grow it to your financial-independence number by your target retirement age. You still work to cover today's expenses — you just no longer need to save for retirement.
How is the Coast FIRE number calculated?
It is your FIRE number (annual expenses ÷ safe withdrawal rate) discounted back to today by your expected real (inflation-adjusted) return over the years until retirement. In short: fiNumber ÷ (1 + real return)^years. The more years you have, the smaller the number, because compounding has more time to do the work.
What's the difference between Coast FIRE and FIRE?
FIRE (financial independence) is the point where your portfolio can cover your expenses and you could stop working. Coast FIRE is earlier and smaller: it's the point where you can stop saving for retirement, because your existing investments will coast to your FIRE number on their own. Reaching Coast FIRE doesn't mean you can stop working — only that you can ease off retirement saving.
Do I stop working when I reach Coast FIRE?
No. Reaching Coast FIRE means you no longer need to save for retirement — your invested money can grow to the goal by itself. You still work to pay for your current lifestyle. That's what makes it a motivating, achievable milestone well before full financial independence.
How does my retirement age change the number?
A later retirement age gives your investments more years to compound, which lowers the Coast FIRE number you need today. An earlier retirement age leaves fewer compounding years, so you need more invested now. Time is the single biggest lever.
Does this include taxes?
No. This is an educational model that does not account for taxes, account types (401(k)/IRA/ISA), fees, Social Security, pensions, or healthcare costs. Real outcomes will differ once those are considered.
Are the results in today's dollars?
Yes. Everything is shown in today's dollars using an inflation-adjusted (real) return, so your future goal and the projection are directly comparable to what you spend today. Contributions are assumed to hold their purchasing power over time.
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Educational use only
Educational purposes only. Calculator results are estimates based on assumptions and user inputs. They are not financial, investment, legal, or tax advice. Investing involves risk, including possible loss of principal. Past performance does not guarantee future results.