Every Coast FIRE calculator on the internet is built for a 32-year-old, where thirty years of compounding does the heavy lifting. This one is built for the runway you actually have. The number it gives you will probably be larger than you were hoping. But that’s the point.
What this is actually telling you
Coast FIRE is the point where you can stop adding to your investments and still land on your number, because growth alone gets you the rest of the way. You keep working. You just stop saving. The paycheck covers today, and the portfolio handles the future on its own. It’s one variant of a broader financial-independence framework, and the gentlest one to aim at from a standing start.
The catch is that the whole idea runs on time, and time is the one input you can’t top up. At 30, compounding does roughly five-sixths of the work for you. At 52, it does about half. Same target, same returns, just fewer years for the math to run. That shorter runway changes most of the money decisions that come after 50, not just this one.
| Stop saving at | You’d need invested | Share of the full number | Years of growth left |
|---|
What this calculator does not know
It is a projection, not a forecast, and definitely not a promise. It runs one smooth return every year. Real markets don’t do that, and the gap matters more the closer you are to drawing on the money:
- Sequence-of-returns risk. A bad first few years of retirement damages a portfolio far more than the same bad years two decades earlier, because you’re selling into the fall. A 52-year-old has less time to recover from one than a 32-year-old does, and this calculator can’t see it.
- Your Social Security figure is an estimate, and the amount changes a lot depending on the age you claim. Pull your real number from ssa.gov rather than guessing.
- Health insurance before Medicare is the line most early-retirement plans get wrong, and for a 50-something it can be the single biggest item between stopping work and 65.
- Everything is in today’s money. The “real return” input is what does that: your expected return minus inflation. It’s why 5% here is not the same as the 8% you might see quoted elsewhere.
- Tax treatment isn’t modeled. A dollar in a Roth and a dollar in a traditional 401(k) are not the same dollar when you spend them.
Questions people actually ask
Is Coast FIRE realistic if I’m starting at 50?
Realistic, yes. Easy, no. The honest version: if you’re 52 and haven’t got roughly half your target invested, full Coast FIRE probably isn’t available in the time you have. What often is available is partial coasting: cutting contributions rather than stopping them. That buys back time and pressure now without abandoning the plan.
Why does my number drop so much when I add Social Security?
Because the portfolio only has to cover the gap between your spending and everything else coming in. At a 4% withdrawal rate, every $1,000 a year of Social Security removes $25,000 from the target, and compounding then shrinks that further back to today. It’s the single biggest lever on this page for anyone over 50, and the one most FIRE calculators leave out because their audience is decades away from claiming.
What if I’ve already passed my Coast FIRE number?
Then the arithmetic says the saving is done and the remaining question is what you do with the money you’re no longer putting away: work less, change to something you’d rather do, or bring the retirement date forward. Run it again with a lower retirement age and see what happens.
Is a 5% real return reasonable?
It’s a planning figure, not a prediction. Long-run US equity returns have run higher than that after inflation, but a shorter runway gives you fewer years to average out a bad stretch, so planning on a lower number leaves you room to be wrong. Try 4% and 7% and see how much the answer moves. If the plan only works at 7%, it’s fragile.
Information, not advice. This is a projection based on the assumptions you entered. It isn’t a recommendation to save, invest, retire or stop doing any of those, and I’m not a financial adviser. Run the numbers, then take them to someone who is.
