Phase 2 · Wealth & Leverage
Coast FIRE Calculator
There's a moment when retirement quietly takes care of itself — and you can stop saving for good. Find out whether your portfolio has already hit coast, or how close it is.
What is Coast FIRE and how do you calculate it?
Coast FIRE is the point where your invested assets are big enough that compound growth alone — with no further contributions — reaches your full retirement number by your target age. To calculate it, take your FI number (25× target annual retirement spending) and discount it back to today: Coast number = FI number ÷ (1 + growth)^years to retirement.
- You have hit Coast FIRE when your current invested assets are at or above the Coast number.
- Coast FIRE is not financial independence — you still need income to cover today’s living costs; you just stop adding to investments.
- The more years until retirement, the smaller the Coast number, because compounding does more of the work. Hitting it young is dramatically easier.
- The 25× target comes from the 4% rule; use a conservative real growth rate, since a rosy assumption makes the Coast number look closer than it safely is.
Untouched portfolio vs your FI number
Under the hood
The math, fully exposed
We set your FI target, then discount it back to today to find the coast threshold:
FI number = target annual spending × 25 (4% rule)
Years to retirement = target age − current age
Coast FIRE number = FI number ÷ (1 + growth)years
Projected = current assets × (1 + growth)years
You've coasted when current assets ≥ Coast FIRE number
- Time is the lever: the more years until retirement, the smaller the Coast number, because compounding does more of the work. Hitting it young is dramatically easier than hitting it late.
- Coast ≠ done: you still need to earn your living expenses until retirement. Coast FIRE just frees you from the obligation to keep adding to investments.
- Growth assumptions matter: use a conservative real return. A rate that\'s too rosy makes the Coast number look closer than it safely is.
Your directives
What to do next, based on your numbers
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Answers
Frequently asked questions
What is Coast FIRE?
Coast FIRE (sometimes called Coast FI) is the moment you've invested enough that, with no further contributions, compound growth alone will carry your portfolio to your full retirement number by the time you retire. You're not financially independent yet — you still need income to cover today's expenses — but you can stop saving and downshift to lower-stress or part-time work, letting the existing money do the rest.
How is the Coast FIRE number calculated?
Start with your FI number — typically 25× your target annual spending (the 4% rule). Then discount it back to today at your expected growth rate over the years until retirement: Coast number = FI number ÷ (1 + growth)^years. Because compounding has decades to work, the Coast number is far smaller than the full FI number — often less than half.
How is Coast FIRE different from regular FIRE?
Full FIRE means you have enough to live off your portfolio now and never work again. Coast FIRE is an earlier, gentler milestone: you've front-loaded enough that retirement is on autopilot, so you only need to earn your current living expenses from here. It trades the grind of aggressive saving for time and flexibility decades before traditional retirement.
Can I really stop saving once I hit Coast FIRE?
Mathematically, yes — if your growth assumption holds. The caveats: markets are volatile, so a conservative growth rate and some buffer matter; and you still need to fund current life, including healthcare, until retirement accounts unlock. Many people keep saving a little anyway for safety, but hitting Coast FIRE means the pressure is off.