Milestones
Coast FIRE: the day you can stop saving
There is a milestone before financial independence that almost nobody names, and it arrives decades earlier: the day your existing balance will reach your number on its own.
Financial independence gets talked about as a single finish line. You are saving, saving, saving, and then one day you are done. That framing makes the whole project feel binary, which is exactly why so many people give up on it: the number is enormous, it is twenty or thirty years away, and nothing in between feels like progress.
But there is an earlier milestone, and it is the more useful one. It is the point where the money you have already invested will grow into your target on its own, with no further contributions at all. After that day you still have to cover your living costs, but you never have to save another dollar for retirement. The community calls it coast FIRE. I think of it as the day the machine finishes the job without you.
The number is smaller than you think
This site takes its name from two commas, the $1,000,000 that supports roughly $40,000 a year at a 4% withdrawal rate. So here is the question worth asking: how much do you need invested today for compounding alone to deliver that by age 65?
Worked example
Invested once, never added to, 7% annual return, target $1,000,000 at age 65
- At age 25 you need
- $66,780
- At age 30 you need
- $93,663
- At age 35 you need
- $131,367
- At age 40 you need
- $184,249
- At age 45 you need
- $258,419
- At age 50 you need
- $362,446
A 30-year-old with $93,663 invested can stop contributing to retirement forever and still have roughly a million dollars at 65. Not because they saved more later, but because 35 years of compounding did the remaining work.
Notice how steeply the number climbs with age. The 25-year-old needs $66,780. The 50-year-old needs $362,446, about five and a half times as much, for the same destination. That gap is not a moral lesson about discipline. It is just the cost of having fewer doubling periods left.
Every year you delay does not add a year of saving. It removes a year of compounding, and the years at the end are the ones doing the heaviest lifting.
Getting to the coast number is a short project
The reason this milestone is worth naming is that it is reachable on an ordinary timeline. Starting from zero, here is how long it takes to accumulate that age-30 figure of $93,663:
Worked example
Building to $93,663 from a standing start, 7% annual return
- Saving $500 per month
- 10.6 years
- Saving $1,000 per month
- 6.2 years
- Saving $1,500 per month
- 4.5 years
- Saving $2,000 per month
- 3.5 years
Six years of serious saving in your twenties buys you the right to never save for retirement again. That is a very different proposition from "save aggressively for thirty years."
What coasting actually buys
The word "coast" is misleading, because it sounds like retirement. It is not. You still have to earn enough to cover your living costs. What changes is that none of that income has to be saved, and that turns out to be worth a great deal.
Consider someone earning $95,000 who hits their coast number. They can now take a 30% pay cut, dropping to $66,500, and the only thing affected is their current lifestyle. Their retirement date does not move, because nothing further was going to be contributed anyway. That is what the milestone actually purchases:
- The freedom to take the interesting job. The one that pays less, at the smaller company, or in the field you actually care about.
- The freedom to work less. Four days a week, or a seasonal schedule, or a long gap between roles without a spreadsheet crisis.
- The freedom to take a real risk. Starting something, or going back to school, with a retirement plan that is already funded and quietly compounding in the background.
- The freedom to stop optimizing. No more agonizing over every dollar, because the dollars that mattered most are already working.
This is the honest appeal of financial independence for most people. Not never working again, but removing the financial penalty from choosing what work you do.
Three ways this number will mislead you
I would be doing you a disservice if I published that first table without the caveats, because coast FIRE is one of the easiest concepts in personal finance to talk yourself into prematurely.
1. That million is not in today's dollars
The 7% figure is a nominal return. Inflation quietly eats into it, so $1,000,000 in 2061 will not buy what $1,000,000 buys now. If you want a million dollars of today's purchasing power, you have to run the same math on a real return of roughly 5%, and the numbers get considerably less comfortable:
| Age | Nominal (7%) | Today's dollars (5% real) |
|---|---|---|
| 25 | $66,780 | $142,046 |
| 30 | $93,663 | $181,290 |
| 35 | $131,367 | $231,377 |
| 40 | $184,249 | $295,303 |
| 45 | $258,419 | $376,889 |
| 50 | $362,446 | $481,017 |
The real-return column is roughly double the nominal one. Use it. A coast number that ignores inflation is a coast number that leaves you short at exactly the moment you cannot fix it.
2. It is only as good as your spending assumption
The whole calculation rests on the target, and the target rests on what you expect to spend. A million dollars supports about $40,000 a year at a 4% withdrawal rate. If your actual retirement spending is $55,000, your number was never $1,000,000, it was $1,375,000, and you coasted to the wrong finish line.
Lifestyle tends to drift upward over a career. The coast number you calculate at 30, based on the life you have at 30, may describe a life you would no longer accept at 55. Recalculate every few years.
3. You are giving up a very large amount of money
Coasting is a real trade, not a free upgrade, and the size of the trade deserves to be stated plainly:
Worked example
Age 30, coast number reached, 35 years at 7%
- Stop saving entirely
- $1,000,000
- Keep saving $1,000 per month
- $2,658,843
- What coasting costs you
- $1,658,843
Continuing to save turns one comma-pair into more than two and a half. Coasting is not the optimal financial choice; it is a deliberate purchase of time and flexibility, paid for in future dollars. That can be entirely worth it, but you should know the price.
How to use this
Treat the coast number as a checkpoint rather than a destination. Work out yours: take the amount you expect to need, divide by 1.05 raised to the number of years until you want it, and you have your figure in today's dollars. Then keep saving anyway, but with the knowledge that the floor beneath you is already built.
Because the psychological effect is the real prize here. "Thirty more years of saving" is a sentence that makes people quit. "Six focused years, and then the compounding covers retirement while I decide what I actually want to do" is a sentence people finish. The savings rate still determines how fast you get there, the order of operations still decides where each dollar goes, and you still have to hold through the bad years. Coast FIRE just gives you a milestone you can actually reach while the big one is still far away.
The bottom line
Full financial independence is a long way off for most people, and treating it as the only milestone makes it easy to abandon. The day your existing investments can finish the job alone arrives far sooner, and it is worth knowing where it sits. Run the number in today's dollars, be honest about what you will actually spend, and accept that coasting costs you real money in exchange for real freedom.
Then decide, deliberately, whether you want to coast or keep climbing. Both are defensible. Drifting past the milestone without noticing it is the only bad outcome.