Coast FIRE by age
Coast FIRE is the moment your invested savings are large enough to grow into your full FIRE number by retirement age with no further contributions. The single biggest factor in how much you need is your age — because the whole idea runs on compounding, and younger savers have far more of it ahead. This page shows the coast number by age, the math behind it, and how to read it for your own target. It's general education, not financial advice.
How much you need invested today, by age
The table below shows the lump sum you'd need today — with zero future contributions — to coast to two common targets by age 65, assuming a 5% real (after-inflation) return. Find your age, and the number is roughly what gets you to "work-optional on autopilot."
| Current age | Years to 65 | Coast to $1,000,000 | Coast to $1,500,000 |
|---|---|---|---|
| 25 | 40 | ~$142,000 | ~$213,000 |
| 30 | 35 | ~$181,000 | ~$272,000 |
| 35 | 30 | ~$231,000 | ~$347,000 |
| 40 | 25 | ~$295,000 | ~$443,000 |
| 45 | 20 | ~$377,000 | ~$566,000 |
| 50 | 15 | ~$481,000 | ~$722,000 |
The jump is dramatic: a 25-year-old needs about $142,000 to coast to $1M, while a 50-year-old needs roughly $481,000 for the same target — more than three times as much, for the same finish line.
The math behind it
Coast FIRE is just compound growth in reverse. To find the coast number, divide your FIRE target by growth over the years remaining: coast number = target ÷ (1 + r)n, where r is your real return and n is years to retirement. For a $1,000,000 target at 5% real with 35 years left (age 30): 1,000,000 ÷ 1.0535 ≈ $181,000. Change the return and every number moves — a cautious 4% real raises the age-30 figure to about $253,000, while an optimistic 6% drops it near $130,000.
Why younger is so much cheaper
Each year of growth multiplies, so the years you have left matter more than the amount you add. At 25 you have 40 years for money to roughly seven-fold at 5% real; at 50 you have 15 years and barely a two-fold. That's why hitting Coast FIRE early — even with a modest balance — quietly does more work than years of later contributions. It's also why the most valuable move in your 20s and early 30s isn't a bigger number, it's time in the market.
Reading it for your own target
Your FIRE number isn't $1M for everyone — it's your annual spending divided by your safe withdrawal rate (spending × 25 at 4%). If you'll spend $50,000/yr, your target is about $1.25M; if $32,000/yr (a Lean FIRE budget), about $800,000. Scale the table to your own goal, or skip the arithmetic entirely and let the Coast FIRE calculator compute your exact number from your age, spending, and return.
Frequently asked questions
How much should I have invested at 30 for Coast FIRE?
Roughly $181,000 to coast to a $1,000,000 target by 65 at a 5% real return — or about $145,000 for an $800,000 lean target. The figure scales with your own spending: target equals annual spending times 25 at a 4% withdrawal rate.
Does Coast FIRE assume I stop working?
No. It assumes you stop contributing to investments. You keep working to cover your current living costs, but your portfolio is left alone to grow to your FIRE number on its own. That's what makes work optional later without saving another dollar.
What if I'm already past 50?
Coast FIRE is still real, it just needs a larger starting balance because less compounding remains. Many people past 50 combine a partial coast with a few more years of contributions, or aim for Barista FIRE — letting part-time income cover the gap while the portfolio finishes growing.
What is the Coast FIRE number by age?
It's the amount you need invested today so that, with no further contributions, growth alone reaches your full FIRE number by retirement. It rises with age because older savers have fewer years of compounding: a $1,000,000 target by 65 needs roughly $181,000 at 30 but about $481,000 at 50, at a 5% real return.
Why does Coast FIRE get harder the older you are?
Coast FIRE relies entirely on compounding over the years until retirement. At 30 you have 35 years for money to grow; at 50 you have only 15. Fewer years means each dollar invested multiplies less, so you need a much larger starting balance to coast to the same target.
What return should I assume for Coast FIRE by age?
Use a real (after-inflation) return so the target stays in today's dollars. A common planning range is 4% to 6% real for a stock-heavy portfolio. The tables here use 5% real; a more conservative 4% raises every coast number, and 6% lowers it.
Find your exact number: run your age, spending and return through the Coast FIRE calculator, set your target with the FIRE number calculator, or see when you'll reach full independence with the early retirement calculator.
Last reviewed: June 2026