Coast FI Explained: How to Tell If You've Already Saved Enough
Coast FI is the point where the money you've already saved will grow, on its own, into what you'll need by retirement — even if you never contribute another dollar. It's one of the more useful numbers in personal finance, and almost nobody checks it.
What "Coast FI" actually means
Financial Independence (FI) usually gets talked about as one big number — the total you need saved to stop working entirely. Coast FI is a quieter, earlier milestone: the point where your current balance, left alone to grow at a normal market return, would reach your retirement target by the time you actually retire. You don't need to add anything else. Compounding does the rest of the work.
Why it's worth checking even if you're not chasing FI
You don't have to want to retire early to care about this. Reaching Coast FI just means your retirement math has real slack in it — a job loss, a career change, a year of lower income, or a deliberate slowdown in contributions won't quietly wreck your retirement timeline the way it would if you were still depending on every future dollar showing up on schedule.
The actual calculation
Take your current retirement balance, project it forward with zero further contributions at a reasonable assumed return (7% is a common long-run average), out to your planned retirement age. Compare that number to your actual retirement benchmark for that age (a common rule of thumb: roughly 10x your income by 67, scaled down for earlier ages). If the zero-contribution projection already clears the benchmark, you've hit Coast FI.
What changes once you're there
Reaching Coast FI doesn't mean stop saving — it means your retirement savings specifically have caught up to where they need to be, so extra money can go toward other goals (a house, current lifestyle, a career risk) without quietly starving your retirement plan. It's permission to redirect, not permission to stop entirely.
The number people usually get wrong
The most common mistake is comparing today's balance to today's target instead of projecting it forward. $80,000 saved at 30 looks nowhere close to a 6-figure retirement target — until you actually run the growth math out to 65 and see what 35 years of compounding does to it untouched.
Check your actual Coast FI status
Grade My Finance Pro includes a Coast FI check built directly into your retirement projection — using your real balance, age, and income, not a generic rule of thumb.
See My Retirement Readiness →Frequently asked questions
Does Coast FI assume I stop working entirely?
No — it specifically means you stop contributing to retirement accounts, not that you stop working. Most people who hit Coast FI keep working, just without the pressure of also needing to max out retirement savings every year.
What return rate should I use to check this?
7% is a commonly used long-run average for a diversified stock-heavy portfolio, though it's an assumption, not a guarantee. Running the number at a slightly more conservative rate (5-6%) gives a more cautious estimate if you want extra margin.
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