Coast FIRE at 50
The short answer
At 50, about $770,000 invested reaches a $1,600,000 retirement by 65 with no further saving. You have 15 years of compounding, which multiplies the balance 2.1 times at a 5% real return. That target funds $60,000 a year at 3.75%.
Check it against your balance
The return assumption carries most of the weight here. Change it and watch how much.
The number at other spending levels
| Spend per year | Retirement target | Coast number now |
|---|---|---|
| $40,000 | $1.07M | $513K |
| $60,000 | $1.60M | $770K |
| $80,000 | $2.13M | $1.03M |
| $100,000 | $2.67M | $1.28M |
The number at other retirement ages
| Retire at | Compounding years | Coast number now |
|---|---|---|
| 55 | 5 | $1.34M |
| 60 | 10 | $1.05M |
| 65 | 15 | $770K |
| 67 | 17 | $698K |
On $60,000 a year. Retiring earlier needs more capital twice over: less time to compound, and a longer retirement that lowers the safe withdrawal rate.
What five years is worth
The same retirement costs $603,000 to coast toward at 45, $770,000 at 50, and $982,000 at 55. Nothing about the plan changed across those ten years. Only the runway did.
Waiting from 50 to 55 adds $212,000 to what you have to accumulate. That is the compounding argument stated as a bill rather than a principle, and it is why Coast FIRE is the milestone worth chasing in your twenties and thirties rather than the full number.
The mechanism is dull and that is the point. A dollar invested at 50 multiplies 2.1 times by 65 at a 5% real return. Five years later it multiplies less, so more dollars are needed to land in the same place.
Worth knowing: coasting is not fire and forget. Check once a year that the balance is still on the path, because two things move: markets, and your spending. Caught early the fix is a couple of years of partial contributions. Left for a decade it is a different retirement date. What Coast FIRE actually buys you goes into where the plan breaks.
Common questions
What is the Coast FIRE number at 50?
About $770,000 at 50, if you want to spend $60,000 a year from 65. That balance grows 2.1 times over the 15 years in between at a 5% real return, reaching the $1,600,000 the plan needs. From that point you can stop saving and still retire on schedule.
What happens if I wait until 55?
The number rises from $770,000 to $982,000, so waiting five years costs $212,000 of extra capital for the same retirement. Nothing changed except the runway. That is the entire argument for saving early stated as one number.
Does Coast FIRE mean I stop saving?
It means you can, not that you should. Most people who hit the number keep contributing, because it pulls the retirement date forward or raises the budget. What changes is that a career break, a pay cut or a lower-stress job no longer costs you the retirement date. That optionality is the point rather than the permission to stop.
What return should I assume?
Use a real return, meaning after inflation. Around 5% is a common assumption for a stock-heavy portfolio and it is what this page uses. If you discount at 8% because that is the historical nominal average, the coast number comes out roughly 40% too small and the shortfall only shows up with a decade left to fix it. Try 4% on this page and watch the number move.
Related: What is Coast FIRE, Barista FIRE, Spending levels, All ages.