Coast FIRE is the point where you have enough invested that compound growth alone will reach your retirement target by the age you plan to retire, without adding another dollar. You still work to cover your current expenses, but you no longer have to save for retirement, so you can downshift to a lower-paying or part-time job.

How is the Coast FIRE number calculated?

Take your FIRE number, which is your annual retirement spending divided by your withdrawal rate, then discount it back to today at your expected real return over the years until retirement. The result is the amount that, growing on its own, reaches your FIRE number by retirement. For example, a 1,000,000 dollar target 30 years out at a 5 percent real return needs about 231,000 dollars invested today.

What is the difference between Coast FIRE and Barista FIRE?

Coast FIRE means your invested savings will grow to your full target on their own, so you only need to earn enough to cover current spending. Barista FIRE is similar but assumes you keep a part-time job, often for income and health benefits, to cover part of your expenses while your investments keep compounding. Coast FIRE is about having stopped saving; Barista FIRE is about how you bridge the years before a traditional retirement.

What does my result mean?

If you have reached Coast FIRE, you can stop saving for retirement and still expect to hit your target, though saving more would let you retire earlier or spend more. If you have not, the gap is what your balance and ongoing contributions still need to cover, and the age shown is when continued saving would get you there.

Coast FIRE Calculator

Find your Coast FIRE number: the amount invested today that grows on its own to your FIRE target by retirement, so you can stop saving for retirement.

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Coast FIRE number

$226,612.86

FIRE number at retirement: $1,250,000.00
Coast FIRE status: Not yet Coast FIRE
Surplus or gap: -$176,612.86
Age you can start coasting: 58

Your balance vs the Coast FIRE target

Quick answer: With the example inputs this page loads by default, the headline result (Coast FIRE number) comes to $226,612.86. Find your Coast FIRE number: the amount invested today that grows on its own to your FIRE target by retirement, so you can stop saving for retirement. Change any input above and every figure updates instantly in your browser.

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Fact-check: results on this page are verified against an independently coded reference oracle that covers all 106 calculators on this site. See how we verify .

Coast FIRE is the point where the money you already have invested will grow on its own to your full retirement target by the age you plan to retire, so you can stop adding new savings and just cover your living costs. This calculator finds that number in today's dollars, tells you whether you have reached it, and shows the age you could start coasting.

What this result means

If your current investments are at or above the Coast FIRE number, you have reached Coast FIRE: future contributions are optional and growth alone should carry you to your target, though saving more would let you retire sooner or spend more. If you are below it, the gap is what your balance and ongoing contributions still need to cover before you can coast, and the age shown is when continued saving would get you there. The number rises as you near retirement, because fewer years are left for compounding.

The takeaway in one line

Gap to coasting: $176,613 more today, or keep saving to coast at age 58

Assumes $50,000 retirement spending, retiring at 65, 5% real return, 4% withdrawals. Illustrative estimate, not advice.

Assumptions

Everything is modeled in today's dollars (real terms). The return you enter is already after inflation, so your retirement spending, your FIRE number, and your Coast FIRE number all stay in today's purchasing power rather than a nominal future projection.
Your FIRE number is your annual retirement spending divided by your withdrawal rate, the inverse of the 4 percent rule (a 4 percent rate gives 25 times your spending). The withdrawal rate is the share of your portfolio you assume you can spend each year without running out.
The Coast FIRE number is your FIRE number discounted back to today at your real return over the years until retirement, so your current balance growing on its own with no further contributions would reach the FIRE number by your retirement age.
You have reached Coast FIRE when your current investments are at or above the Coast FIRE number. The surplus or gap is your current investments minus that number, so a negative figure is what you still need to cover.
The age you can start coasting is the first age at which your current investments plus your continued annual contributions, both growing at the real return, reach the rising Coast FIRE number for that age. It is your current age when you are already there, and it is blank when your contributions do not reach it by your planned retirement age. The target rises each year because fewer years are left to compound, so a balance with no contributions and no surplus never crosses it.
Contributions are added at the end of each year and grow at the same real return as your existing balance, using the shared time-value engine rather than a re-derived formula. Growth is applied annually.
Not modeled: taxes, Social Security or other income, any employer match beyond what you enter as a contribution, changing contributions or returns over time, and sequence-of-returns risk, where poor returns early in retirement can drain a portfolio even when long-run averages hold.
Results are rounded to the nearest cent, with ages shown as whole numbers. This is an estimate for educational purposes only, not financial, legal, or tax advice. Consult a qualified professional for guidance specific to your situation.

Key terms

Definitions for the terms this calculator uses, in our finance glossary .

What is Coast FIRE?

Coast FIRE is the moment your invested savings are large enough that compound growth alone will carry them to your full retirement target by the age you plan to retire. Once you reach it, you no longer have to save for retirement. You only need to earn enough to cover your current spending, so you can downshift to a lower-paying or part-time job and let the portfolio coast.

Two numbers drive it: your FIRE number (the target you eventually need) and your Coast FIRE number (how much of it you need today).

Your FIRE number is your annual retirement spending divided by a safe withdrawal rate:

FIRE number = annual spending / withdrawal rate

At the common 4% rate that is 25 times your annual spending. Your Coast FIRE number is that target discounted back to today at your expected real return over the years until retirement:

Coast FIRE number = FIRE number / (1 + real return)^years to retirement

If your current investments are at or above the Coast FIRE number, growth alone reaches your FIRE number by retirement and you have reached Coast FIRE.

In today’s dollars (real terms)

This calculator works entirely in today’s dollars. The return you enter is a real return, meaning after inflation, so your spending, your FIRE number, and your Coast FIRE number all stay in today’s purchasing power. That avoids guessing what a future dollar will buy. A common long-run real return estimate for a diversified portfolio is around 5%.

Worked example

Age 30, retiring at 65, $50,000 invested, contributing $12,000 a year, $50,000 of annual spending in retirement, a 5% real return, and a 4% withdrawal rate:

FIRE number = $50,000 / 0.04 = $1,250,000.
Years to retirement = 65 - 30 = 35.
Coast FIRE number = $1,250,000 / (1.05)^35 = $226,612.86. That is what you would need invested today to coast.
You have $50,000, so you are not there yet: the gap is about $176,613.
Adding $12,000 a year, your balance reaches the rising Coast FIRE target at age 58, so continued saving lets you stop and coast seven years before your planned retirement.

How the coasting age is found

The Coast FIRE number is not fixed over time. As retirement nears, fewer years are left to compound, so the amount you would need to coast rises each year. The calculator walks forward year by year, growing your current balance plus your continued contributions at the real return, and compares it with the Coast FIRE target for that age. The first age the balance meets the target is the age you can start coasting. If your balance has no surplus and you add nothing, it grows at the same rate as the target and never catches up, which is why some scenarios never reach Coast FIRE without more saving.

How reliable is the 4% rule?

The 4% rule comes from the Trinity study, which looked at U.S. historical returns and found that withdrawing 4% of a starting portfolio, adjusted for inflation, rarely exhausted it over 30 years. It is a useful guideline, not a guarantee. The main risk is sequence-of-returns risk: poor returns early in retirement can permanently shrink a portfolio even when long-run averages are fine. Early retirees with horizons longer than 30 years often plan for a lower rate, such as 3.5%. This is an estimate for planning, not financial advice.

Sources

Cooley, Hubbard, and Walz, the Trinity study on sustainable withdrawal rates.
Standard present-value and future-value-of-an-annuity math, applied in real (inflation-adjusted) terms.

Frequently asked questions

What is Coast FIRE?: Coast FIRE is the point where you have enough invested that compound growth alone will reach your retirement target by the age you plan to retire, without adding another dollar. You still work to cover your current expenses, but you no longer have to save for retirement, so you can downshift to a lower-paying or part-time job.
How is the Coast FIRE number calculated?: Take your FIRE number, which is your annual retirement spending divided by your withdrawal rate, then discount it back to today at your expected real return over the years until retirement. The result is the amount that, growing on its own, reaches your FIRE number by retirement. For example, a 1,000,000 dollar target 30 years out at a 5 percent real return needs about 231,000 dollars invested today.
What is the difference between Coast FIRE and Barista FIRE?: Coast FIRE means your invested savings will grow to your full target on their own, so you only need to earn enough to cover current spending. Barista FIRE is similar but assumes you keep a part-time job, often for income and health benefits, to cover part of your expenses while your investments keep compounding. Coast FIRE is about having stopped saving; Barista FIRE is about how you bridge the years before a traditional retirement.
What does my result mean?: If you have reached Coast FIRE, you can stop saving for retirement and still expect to hit your target, though saving more would let you retire earlier or spend more. If you have not, the gap is what your balance and ongoing contributions still need to cover, and the age shown is when continued saving would get you there.

Related calculators

Learn how this works

New to this topic? Our companion guide explains it in plain language: Coast FIRE: When You Can Stop Saving for Retirement

By Sam Sage Last reviewed July 2026.