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Coast FIRE Calculator

Find the moment you can stop saving for retirement — and let compound growth carry you the rest of the way.

Updated May 2026 · Reviewed against current market data

Current age
18 yr70 yr
Target retirement age
When you want to fully stop working
36 yr80 yr
Annual retirement expenses
Today's lifestyle, post-retirement
$0$10.0 M
Current investments
401(k), IRA, brokerage, etc.
$0$50.0 M
Monthly contribution
$0$500 K
Expected annual return
Real (inflation-adjusted) return
1%15%
Coast FIRE NumberLive
$230,311
Need $110 K more$50.0 K/yr · retire at 60 · 7% real return
See full breakdown
Not yet coasting
You're 52% of the way to Coast FIRE.
Keep going — Coast FIRE in ~3.8 years.
Coast progress52%
$120 K / $230 K
Halfway home. The back half compounds faster.
Your coasting window
39
→ age 60
21 yr of pure compounding
Optional contributions for ~21 years.
FIRE number
$1.3 M
25× annual expenses
At retirement (coasting)
$651 K
Short by $599 K
Coast FIRE date
Feb 2030
3.8 yr · age 39
To reach Coast FIRE by age 60, save
$0/ month
You're already saving enough — every extra dollar shortens your runway.

Coast phase timeline

Contributing → Coasting → Retired
Starting at $120 K with $1.5 K/mo at 7% real return. Solid green = coast path. Dashed blue = keep contributing.
Barista FIRE
You're not quite at Barista FIRE. To qualify: reduce retirement expenses to $30.6 K/yr or add $16.4 K/yr in part-time income to bridge the gap.
Barista FIRE = stop full-time work, cover today's expenses with light work, let compound growth finish the job.
What if you tweak it?
  • +$300/mo (on top of your $1.5 K) could get you to Coast FIRE 0.5 years sooner.
  • Cutting expenses by 10% lowers your Coast FIRE target by $23.0 K.
  • Pushing retirement +5 years drops your Coast FIRE number by $66.1 K.
Your next step

About the Coast FIRE calculator

A Coast FIRE calculator that shows the lump sum you need invested today so compound growth alone reaches your FIRE number by retirement. Compare your current investments against the Coast FIRE target, see when you can stop contributing, and explore Barista FIRE scenarios with a live coasting-phase timeline.

How it works

  1. 1
    Enter your current age & target retirement age
    The gap between them is your runway for compound growth. Even 20 years at 7% roughly quadruples your money — and that's the magic Coast FIRE relies on.
  2. 2
    Set your annual retirement expenses
    What it'll cost to live the lifestyle you want in retirement, in today's dollars. We multiply by 25 (the 4% rule) to get your full FIRE number.
  3. 3
    Add your current investments
    All retirement-earmarked assets — 401(k), IRA, brokerage, taxable savings. Exclude your home unless you'll downsize.
  4. 4
    See your Coast FIRE number
    We discount your FIRE number back to today using your expected return. If your current investments already meet that smaller number, you've reached Coast FIRE and contributions become optional.

This calculator is a planning tool, not financial advice. Results are projections based on the assumptions below — actual market returns vary. See the Methodology page for full editorial standards and data sources.

Return rate source
S&P 500 inflation-adjusted (real) long-run average (~7%), from Prof. Robert Shiller's Yale dataset. Entered as a real return — all dollar figures are in today's purchasing power.
FIRE number basis
Annual Expenses × 25, derived from the 4% safe withdrawal rate (Trinity Study, Cooley, Hubbard & Walz, 1998). Coast FIRE Number = FIRE Number ÷ (1 + r)^years.
Compounding
Annual compounding for the present-value discounting of the FIRE number back to today. Monthly compounding for the accumulation phase (contributions before coasting).
Tax treatment
Not modelled. Enter return as a real, after-tax rate. If invested in tax-advantaged accounts (401k, IRA, ISA, NPS), effective drag is minimal — validate your final number against your tax situation.
Not accounted for
Social Security income, contributions during the coast phase (model assumes zero new contributions after coasting begins), and variable spending in retirement.

Frequently asked questions

  • Coast FIRE is the point at which your existing investments are large enough that compound growth alone (no further contributions) will reach your full FIRE number by your target retirement age. You can keep working to cover living expenses, but you no longer *have* to save for retirement — your nest egg is already on autopilot.

  • Coast FIRE Number = FIRE Number ÷ (1 + annual_return)^years_to_retirement, where FIRE Number = Annual Expenses × 25. So a 35-year-old targeting $50k/yr at 60 with a 7% return needs $1,250,000 ÷ (1.07)^25 ≈ $230,000 invested today.

  • Full FIRE means your portfolio is already large enough that you can stop working entirely — withdraw 4% a year and live off it. Coast FIRE is an earlier milestone: you still need a paycheck to cover today's expenses, but you no longer need to save for retirement. The portfolio coasts on its own.

  • Barista FIRE is Coast FIRE plus part-time work — typically just enough to cover current expenses and health insurance. You stop saving aggressively, downshift to a lower-stress job (the canonical example being a barista with employer-subsidised insurance) and let your portfolio compound to full FIRE in the background.

  • Once your invested portfolio crosses the Coast FIRE number for your target retirement age and expected return. From that point, any additional contributions just speed up retirement or upgrade the lifestyle — they're no longer required.

  • Compound growth is exponential. At 7%, money roughly doubles every 10 years — so $100k at age 35 becomes ~$400k by 55 and ~$800k by 65 without adding a dime. After your Coast FIRE moment, time does the heavy lifting; contributions become marginal.

  • 7% is the long-term inflation-adjusted return on a US equity index (S&P 500). Use 5–6% for a more conservative balanced portfolio, or 8%+ only if you're comfortable with higher equity volatility and a long horizon.

  • The return rate should be entered as a real (inflation-adjusted) return — so all dollar figures stay in today's purchasing power. Taxes are not modelled; if your investments are in tax-advantaged accounts (401(k), IRA, ISA, NPS) the impact is minimal, but you should validate the final FIRE number against your effective tax rate.

Sources

All FIRE calculations on this site are grounded in peer-reviewed academic research and long-run historical data. See the Methodology page for full editorial standards.

  1. [1]Cooley, Hubbard & Walz (Trinity Study). Retirement Savings: Choosing a Withdrawal Rate That Is Sustainable (1998, updated 2011)
  2. [2]Prof. Robert Shiller, Yale University. S&P 500 Historical Annual Returns (inflation-adjusted, 1871–present) (ongoing)
  3. [3]William P. Bengen. Determining Withdrawal Rates Using Historical Data (1994, Journal of Financial Planning)
  4. [4]Wade D. Pfau. Safe Savings Rates: A New Approach to Retirement Planning over the Life Cycle (2011, Journal of Financial Planning)
  5. [5]Michael Kitces. The Ratcheting Safe Withdrawal Rate — A More Dominant Version of the 4% Rule (and earlier SWR analysis for early retirees) (2012, Nerd's Eye View)

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