Coast FIRE calculator
Use the Coast FIRE calculator to find the balance that, left alone, compounds into your full retirement target without another dollar of new contributions. The Coast FIRE calculator shows the formula, your target divided by a compound-growth factor for your years to retirement, and runs at a real return so the answer is in today's dollars.
401(k)/403(b), IRAs, HSA, taxable brokerage
5.0%–6.0% is the more conservative planning range; 7.0% matches long-run historical stock averages
Only used to estimate years to close a gap below your Coast FIRE number
Your Coast FIRE number
$197,050.68
| The arithmetic | $1,500,000 ÷ (1.07)^30 = $197,050.68 |
| Full retirement target | $1,500,000 |
| Years to retirement | 30 |
This assumes your entered real return holds every year between now and retirement, not that it will.
Gap to your Coast FIRE number
$77,051
| Percent funded | 60.9% |
| Years to close the gap | 3 years and 5 months |
At 35, this is roughly 13.1% of a $1,250,000 target for a $50,000-spending retirement at 65, per the age-by-age table below.
| Real return | Coast FIRE number |
|---|---|
| 5.0% | $347,066 |
| 6.0% | $261,165 |
| 7.0% (your entry) | $197,051 |
Free stock bonuses
Your Coast FIRE number is $197,051 and you have $120,000 invested today. These brokerages pay a sign-up bonus in stock for opening the account through Tweed's links.
Tweed is paid when you open an account through these links. Terms are each company's own, checked on the date shown.
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Your numbers never leave your browser.
Figures from IRS Notice 2025-67.
How this is calculated
Your full retirement target (annual spending ÷ safe withdrawal rate) gets discounted back to today at your expected real annual return, over the years remaining until your target retirement age.
In this article
- How to use the Coast FIRE calculator
- What your Coast FIRE calculator results mean
- How your Coast FIRE number is calculated
- Understanding Coast FIRE
- Coast FIRE number by age
- What real return should you use in a Coast FIRE calculator?
- Worked example: Coasting at age 35
- Maximizing 2026 tax-advantaged contributions before you coast
- What this Coast FIRE calculator assumes and leaves out
- Related calculators
- Frequently asked questions about Coast FIRE
How to use the Coast FIRE calculator
1. Enter your age and target retirement age
The years between them are how long your money gets to grow on its own. Retiring earlier leaves less time, so the number you need today goes up.
2. Add your current invested balance
Count every invested account: 401(k) or 403(b), IRAs, HSA, and taxable brokerage. Leave out your home, since it doesn't produce income you can withdraw.
3. Set your retirement spending and withdrawal rate
Enter what you expect to spend each year in retirement, in today's dollars. Your spending divided by the safe withdrawal rate is your full retirement target.
4. Pick a real return and an optional monthly contribution
A real return is your expected return minus inflation, which keeps the answer in today's dollars. The note under the field gives a more conservative range. Add a monthly contribution to see how long it would take to close a gap.
What your Coast FIRE calculator results mean
- Your Coast FIRE number, the large figure
- The balance you need invested today so that, with no new contributions, it grows to your full retirement target by your retirement age.
- The arithmetic
- Your full target divided by one plus your real return, raised to your years to retirement. Your own numbers are filled in.
- Full retirement target
- Your planned yearly spending divided by your safe withdrawal rate. This is what you need on the day you retire.
- Years to retirement
- Your target retirement age minus your current age.
- Gap to your Coast FIRE number
- Shown when your balance is below the number. It is your Coast FIRE number minus your current balance.
- You've already reached Coast FIRE
- Shown when your balance meets or beats the number. The large figure is how far above it you are.
- Percent funded
- Your current balance divided by your Coast FIRE number.
- Years to close the gap
- How long your monthly contribution would take to reach the number, with your balance and each deposit growing at your real return. It only appears when you enter a contribution.
- The line that starts with your age
- Where your age falls in the fixed reference scenario from the age table further down this page. It does not use your other inputs.
- Coast FIRE number at different return assumptions
- Your number worked out again at the more conservative real returns from the field note, next to your own entry.
How your Coast FIRE number is calculated
Your Coast FIRE number is your full retirement target, discounted back to today's dollars at your expected real rate of return over the years remaining until retirement.
Step 1: Find your full retirement target
Divide your projected annual retirement spending by your safe withdrawal rate. At the standard 4% rate,3that's 25 times your annual spending. The guide to the4% rule explains where that rate comes from.
Step 2: Discount that target back to today
The target divides by (1 + your real return), raised to the number of years until retirement. Real return means nominal market return minus inflation, so the whole calculation stays in today's purchasing power. Years to retirement is your target retirement age minus your current age.
Step 3: Compare it against what you have now
Add up every investable balance you hold: 401(k)/403(b), IRAs, HSA, taxable brokerage. If that total meets or beats your Coast FIRE number, new contributions are optional for reaching your full target. If it falls short, the calculator shows the monthly contribution and time needed to close the gap.
Understanding Coast FIRE
What is Coast FIRE?
Coast FIRE is a milestone inside the broader FIRE movement, short for Financial Independence, Retire Early. You hit it when your invested savings alone are projected to grow into your full retirement number, with nothing more added, and from that point on contributing becomes a choice rather than a requirement. The guide to the FIRE movement covers the wider picture, including the savings-rate math behind the crossover point.
How is Coast FIRE different from regular FIRE?
Regular FIRE means you've reached your full number and can stop working entirely. With Coast FIRE, you still need active income to cover today's bills until you retire.
Coast FIRE number by age
The earlier you start, the smaller a share of your final target you need saved today, because compounding has longer to work.
How the required balance changes across four decades
The table below assumes a $1,250,000 terminal target at age 65 ($50,000 annual spending at a 4% withdrawal rate) and a 7.0% real annual return.
| Age | Years to 65 | Coast FIRE balance needed | % of final target | Growth multiple |
|---|---|---|---|---|
| 25 | 40 | $83,475 | 6.7% | 14.97x |
| 30 | 35 | $117,079 | 9.4% | 10.68x |
| 35 | 30 | $164,209 | 13.1% | 7.61x |
| 40 | 25 | $230,311 | 18.4% | 5.43x |
| 45 | 20 | $323,024 | 25.8% | 3.87x |
| 50 | 15 | $453,058 | 36.2% | 2.76x |
| 55 | 10 | $635,437 | 50.8% | 1.97x |
| 60 | 5 | $891,233 | 71.3% | 1.40x |
A 25-year-old needs less than 7% of the final target saved today. A 55-year-old needs over half, because the compounding window is a third as long.
How your target scales with planned spending
The required balance scales linearly with spending: doubling your planned annual spending doubles your Coast FIRE number at every age. This table assumes retirement at 65, a 4% withdrawal rate and a 7.0% real return.
| Current age | $30,000/yr ($750,000 target) | $40,000/yr ($1,000,000 target) | $50,000/yr ($1,250,000 target) | $60,000/yr ($1,500,000 target) | $80,000/yr ($2,000,000 target) |
|---|---|---|---|---|---|
| 25 | $50,085 | $66,780 | $83,475 | $100,171 | $133,561 |
| 30 | $70,247 | $93,663 | $117,079 | $140,494 | $187,326 |
| 35 | $98,525 | $131,367 | $164,209 | $197,051 | $262,734 |
| 40 | $138,187 | $184,249 | $230,311 | $276,374 | $368,498 |
| 45 | $193,814 | $258,419 | $323,024 | $387,629 | $516,838 |
| 50 | $271,835 | $362,446 | $453,058 | $543,669 | $724,892 |
What real return should you use in a Coast FIRE calculator?
A conservative real return of 5% to 6% protects your Coast FIRE number against a bad decade right after you stop contributing, even though broad US stock indices have historically returned closer to 7% after inflation over long periods.4
Why a 5% to 6% real return is the safer planning assumption
Once you stop contributing, dollar-cost averaging stops smoothing out the down months for you. A downturn that hits early in your coasting period does more damage than the same downturn ten years in, since there's no fresh money going in to buy the dip. Planners call this sequence-of-returns risk, and a lower baseline assumption is the simplest way to build in a margin for it.
How your Coast FIRE number changes at different return assumptions
This table models an investor at 35 targeting $1,500,000 by 65 ($60,000 spending at a 4% rate).
| Real return | Coast FIRE target at 35 | Difference from 7% baseline |
|---|---|---|
| 4.0% | $462,478 | +$265,427 |
| 5.0% | $347,066 | +$150,015 |
| 6.0% | $261,165 | +$64,115 |
| 7.0% | $197,051 | Baseline |
| 8.0% | $149,066 | -$47,985 |
Dropping the assumed return from 7% to 5% raises the age-35 target by about 76%, from $197,051 to $347,066. That's the case for planning on the conservative end.
Worked example: Coasting at age 35
Consider an investor who is 35, plans to retire at 65, expects $60,000 in annual spending, and uses a 4% withdrawal rate. The full FIRE target is $60,000 ÷ 4%, or $1,500,000.
At a 7% real return, discounting that target back 30 years gives a Coast FIRE number of $197,051. If this investor already holds $120,000, they've funded 60.9% of the target, and closing the remaining $77,051 gap takes about 3.4 years at $1,000 a month.
Run your own age, spending, and balance through the calculator above to check your own timeline.
Maximizing 2026 tax-advantaged contributions before you coast
Maxing out tax-advantaged accounts before you coast shrinks the years it takes to hit your number, because the growth compounds tax-deferred or tax-free.
| Account | 2026 limit | Catch-up |
|---|---|---|
| 401(k) / 403(b) / governmental 457(b) elective deferral | $24,5001 | $8,000 at 50+, or $11,250 at ages 60–63 only1 |
| Traditional or Roth IRA | $7,5002 | $1,100 at 50+ (total $8,600)2 |
| HSA, self-only / family | $4,400 / $8,7505 | $1,000 at 55+, not indexed5 |
Participants whose prior-year FICA wages from the plan sponsor exceeded $150,000 must make 2026 catch-up contributions as Roth.1 Use the Tweed 401(k) calculator to model the accumulation phase in detail.
What this Coast FIRE calculator assumes and leaves out
The Coast FIRE calculator takes your projected annual retirement spending, divides it by your safe withdrawal rate to get your full retirement target, then discounts that total back to today using your entered real annual return and years to retirement.
It doesn't model Social Security, taxes on withdrawals, income or employer changes, or a market downturn specifically during your coasting period, which is why the conservative-return range above matters. Tweed rechecks the statutory contribution figures against IRS guidance every year. No government agency publishes a certified long-run market return, so the default assumption is presented as a range rather than a fixed input.
Frequently asked questions about Coast FIRE
Is Coast FIRE realistic on an average salary?
Coast FIRE is realistic on an average salary if you started saving early or kept a high early savings rate, because time, not income, is the biggest lever in the formula. A 25-year-old needs less than 7% of their final target saved today; someone starting at 45 needs a much larger head start.
What accounts count toward your Coast FIRE number?
Every investable retirement account counts toward your Coast FIRE number: 401(k) and 403(b) balances, traditional and Roth IRAs, HSA balances earmarked for retirement, and taxable brokerage holdings. A primary home or other illiquid assets don't count, since they aren't producing income you can withdraw.
Can you stop saving for retirement once you hit Coast FIRE?
Reaching Coast FIRE means your existing balance is projected to compound to your full retirement target without new contributions, so yes, you can stop. You still need active income to cover current living costs, taxes and health coverage until you retire.
Coast FIRE vs. Barista FIRE: What's the difference?
Coast FIRE covers 100% of current spending from active income and takes zero portfolio withdrawals before retirement age. Barista FIRE mixes partial withdrawals with lighter part-time work well before that age, which is a different, earlier tradeoff.
Does Coast FIRE work if you plan to retire before 65?
Coast FIRE works at any target retirement age, but retiring earlier shortens the compounding window and raises the balance you need today. Set your actual target age in the calculator above rather than assuming 65; the age tables on this page use 65 as a reference point, not a rule.
Do you still need an emergency fund once you've coasted?
An emergency fund still matters after you've coasted, yes, because your Coast FIRE number covers retirement, not a job loss or a medical bill today. Keeping a separate cash buffer protects the plan from having to tap retirement savings early.
Personal finance writer, former Forbes contributor and This Week in Fintech writer. He isn't a financial advisor or a CPA.
Sources
- https://www.irs.gov/pub/irs-drop/n-25-67.pdf
- https://www.irs.gov/newsroom/401k-limit-increases-to-24500-for-2026-ira-limit-increases-to-7500
- William Bengen, "Determining Withdrawal Rates Using Historical Data," Journal of Financial Planning, 1994
- https://pages.stern.nyu.edu/adamodar/New_Home_Page/datafile/histretSPX.html
- https://www.irs.gov/pub/irs-drop/rp-25-19.pdf