Coast FIRE Calculator

What Coast FIRE actually is

Coast FIRE is the point at which your invested portfolio is large enough that compound growth alone — without any further contributions — will carry it to your full financial independence number by your target retirement age. You still need to earn enough to cover current living expenses (you are not retired), but the pressure to save aggressively is gone. Every dollar you earn from this point forward is for living, not for your retirement number.

This is often the earliest meaningful FIRE milestone most people hit, achievable 15–25 years before full FIRE for many savers. It changes what kind of work feels acceptable. You can take a lower-paying job you enjoy, reduce hours, take sabbaticals, or start a business — because your retirement is already mathematically handled.

The math, step by step

Start with the endpoint. If you want $60,000 per year in retirement and plan to withdraw 4% annually, you need $60,000 / 0.04 = $1,500,000 at retirement. That is your FIRE number.

Now discount it backward. If you are 35 and want to retire at 65 (30 years), and you expect 7% real returns, you need: $1,500,000 / (1.07)^30 = $197,077 invested today. That is your Coast FIRE number.

If your current portfolio exceeds $197,077, you have reached Coast FIRE. If you contribute nothing more and earn 7% real returns for 30 years, your portfolio grows to $1.5 million. Starting earlier makes it dramatically easier: the same target at age 25 (40 years) requires only $100,186 — 49% less — because of ten extra years of compounding.

Why Coast FIRE is often misunderstood

Two common misunderstandings. First, Coast FIRE is not financial independence. It is the point at which retirement is locked in, not the point at which you stop working. You still need income for current expenses — rent, food, healthcare, everything. You just no longer need to save any of it.

Second, Coast FIRE depends entirely on your return assumption. At 7% real returns, the math works out cleanly. At 5%, you need roughly 40% more capital to hit the same target. If real returns come in below expectations for a sustained period, someone at “Coast FIRE” on paper may find they actually were not. Consider Coast FIRE a strong position with good historical odds, not a guarantee.

What you do at Coast FIRE

Practical options once you hit this milestone:

Reduce hours. Drop from full-time to part-time. You only need to cover current expenses, not save for retirement. A 60% pay cut that comes with a 40-hour-to-20-hour reduction may be perfectly viable.

Change careers. Take a lower-paying job you love. Coast FIRE makes this financially viable where it would not be if you were still accumulating aggressively.

Take sabbaticals. Six months off every few years is affordable when your retirement savings are done and your portfolio compounds unattended.

Keep working as normal. Every additional dollar saved after Coast FIRE brings full FIRE closer. The compounding does not stop just because you have crossed the threshold.

Accumulator perspective

If you have not yet reached your Coast Number, the chart shows two trajectories: your portfolio with continued monthly contributions (solid line) and without any further contributions (dashed line). The gap between them is the value of your ongoing savings. The point where the dashed line crosses the FIRE target is when compounding alone would get you there — but contributions get you there sooner.

Decumulator perspective

If you have already passed your Coast Number — or your full FIRE number — this calculator serves as verification. The chart confirms your portfolio’s projected trajectory without additional contributions. You are past the point where savings change the outcome. Time and returns handle the rest. If you are drawing dividends now and preserving principal, the Dividend Income Calculator provides the income-replacement framing that may be more relevant to your situation.

The return assumption matters more than you think

A 7% real return is the historical S&P 500 average after inflation, and it is what SEC investor.gov uses in examples. But it is an average — individual decades have delivered 15%+ and others have delivered -2%.

Coast FIRE math works well with 7% returns and 30-year horizons. It works less well if the first ten years deliver 2% and you are at Coast FIRE on paper but not in reality. Conservative Coast FIRE planners use 5% real returns — that requires roughly 40% more capital but provides substantial protection against underperformance.

Coast FIRE vs Barista FIRE

Coast FIRE assumes you keep full-time income. You cover current expenses through work, and investments handle retirement on their own. Barista FIRE assumes you shift to part-time work — part-time income covers part of current expenses, with the rest coming from small investment distributions.

Coast FIRE is often the step before Barista FIRE. Someone at Coast FIRE could work full-time until 65 then retire. Or they could shift to part-time at 45, cover 60% of expenses through work, and draw the rest from investments — that is Barista FIRE. Start with this calculator to see if you are at Coast FIRE, then use the Barista FIRE Calculator to model the step after.

What this calculator does not model

Market volatility — returns are not smooth. Sequence-of-returns risk — timing of bad years matters enormously near retirement. Tax drag on taxable accounts. Social Security or pension income — adjust your expense input to account for these. Early retirement healthcare costs before Medicare eligibility at 65. See methodology for full disclosure.