Coast FIRE Calculator
What you have, what you spend, and when you stop
Your result will appear here
Fill in the fields on the left and this updates as you type.
Know what this estimate is based on
- Jurisdiction
- General mathematical model
- Scope and limitations
- Long-range scenario, not a guarantee. Small changes in returns, inflation, fees, taxes, and withdrawal timing can materially change the result.
- Source links checked
- Jul 30, 2026
Built and regression-tested by Smart Tools Lab. It has not been individually reviewed by a licensed financial, tax, or legal professional.
How to use
- 01
Enter the annual spending your portfolio has to fund in retirement, in today's money, then check the withdrawal rate under it. Those two fields are the whole target: spending divided by rate, and the rate opens at 4%.
- 02
Enter your age now and the age you plan to retire. The years between them are the runway compounding gets, and that runway is the only reason a coast number is smaller than a FIRE number.
- 03
Enter what you already have invested for retirement — every account that stays invested until that age, not just the 401(k). The headline gap is measured against this figure and nothing else.
- 04
Enter what you invest each year now and the annual return you expect. The contribution decides how fast the gap closes; the return decides how large the coast number was in the first place.
- 05
Open Advanced options and put in an inflation figure — it opens at 0, which silently reads the return above as a real, after-inflation rate. Then read the gap at the top, the age you reach the coast number, and the table showing the requirement climbing year by year.
Formula
FIRE number in today's money = annual spending ÷ withdrawal rate. At the figures this page opens with, $60,000 ÷ 4% = $1,500,000. The number you actually need in the dollars of your retirement year = that figure × (1 + inflation)^years to retirement, so $1,500,000 × 1.03^33 = $3,978,503. Coast number today = that future target ÷ (1 + return)^years to retirement: $3,978,503 ÷ 1.07^33 = $426,634. The headline gap is the coast number less what you already have invested. The crossing age is not solved with a formula, it is walked: each year the requirement is recomputed against one fewer year of compounding while the balance grows by the return and takes in another contribution, and the coast age is the first year the balance is at or above the requirement. Leaving inflation at 0 makes the two exponents cancel differently — the target stays in today's money and the return is read as a real rate.
Example
Age 32, retiring at 65, $60,000 of spending to fund at a 4% withdrawal rate, $250,000 invested, $24,000 going in each year, a 7% expected return, and 3% typed into the inflation field under Advanced options. The FIRE number in today's money is $1,500,000; by 65 that same life costs $159,140 a year and the target becomes $3,978,503. Discounted back 33 years at 7%, the coast number today is $426,634, so against $250,000 invested the gap is $176,634. At $24,000 a year the balance overtakes the requirement at 43 — $905,019 against a requirement of $898,000 that year — and coasting from that birthday frees $528,000 of contributions across the 22 years to 65. Leave the inflation field at 0 and the same inputs produce the opposite page: the target stays $1,500,000, the coast number falls to $160,852, and the $250,000 is already $89,148 past it.
Definitions
- Coast number
- The balance that, left completely alone, compounds into your full retirement target by the age you plan to retire. It is a discounted figure, so it rises every year you do not reach it.
- Withdrawal rate
- The share of the portfolio drawn in the first year of retirement, indexed for inflation thereafter. It is the divisor that turns spending into a FIRE number: 4% means 25 times spending, 3.5% means 28.6 times.
- Real return
- The return after inflation has been taken out. Enter a real return and leave the inflation field at 0 and every figure on the page is in today's money; enter a nominal return without an inflation figure and the target is understated.
Good to know
What coasting is, and what it is not
Coast FIRE is the moment the saving stops mattering. Enough is invested that, left completely alone, it compounds into the full retirement number by the age you plan to retire — so the contributions can stop while everything else about your life carries on. That is a narrower claim than it sounds, and the narrowness is the point. Coasting assumes you still earn enough to cover every dollar you spend between now and retirement. It assumes you never draw on the portfolio in that time, not for a roof, not for a redundancy, not for a year off. And in the United States it quietly assumes you keep whatever health coverage your job provides, because the moment you have to buy your own the spending figure this page was built on is wrong by five figures a year. None of that is a criticism of the idea; it is the specification. What changes when you cross the line is not your obligations but where the money above them goes. At the figures this page opens with, reaching the coast number at 43 frees $24,000 a year for the 22 years to 65 — $528,000 that no longer has to go into a retirement account. It can buy a four-day week, a career that pays less and is worth more, a mortgage cleared early, a taxable brokerage account that becomes bridge capital for an earlier exit, or simply be spent. Coasting is also the most reversible decision in this whole area. If the market disappoints, or spending turns out higher than planned, you start contributing again, and the cost of the pause is the compounding on a few years of contributions rather than a retirement missed. That asymmetry is what makes it worth calculating even for people with no intention of stopping: knowing the date the saving becomes optional changes how the next decade of work gets chosen.
Why the target rises every year you miss it
A coast number is a discounted figure, and the thing being discounted keeps getting closer. At 32 with 33 years to run, a $3,978,503 target at a 7% return needs $426,634 today. At 33 there are 32 years left to do the same work, so the same target needs $456,498 — $29,864 more for waiting one birthday. Nothing went wrong; the requirement simply climbs at the return rate, because that is what discounting one year less means. This is the single most misread thing about the number, and it is why the page prints the requirement age by age rather than as one figure. Two lines are moving at once. The requirement rises at the return rate and nothing else. Your balance rises at the return rate PLUS whatever you contribute. So a balance that is still being fed always closes the gap eventually, and the year it does is the coast date — found by walking the years rather than solved, because once contributions are in the picture no closed form gives it. At $24,000 a year against a $176,634 gap, the crossing lands at 43: $905,019 of balance against a $898,000 requirement. The consequence worth internalising is that the coast date is a moving target rather than a finish line. Miss it for three years and the requirement has climbed by more than a fifth. Hit it in a year the market is expensive, and a 30% fall the following year moves the date, not just the balance — you would be below the line again, and the honest response is to resume contributing rather than to insist the milestone was passed. The chart on the page exists for exactly this: the crossing point is far easier to see than to read, and the shape of the two lines tells you how much slack you have if one bad year arrives.
The two assumptions doing all the work
Everything on this page is arithmetic except two numbers, and those two numbers decide the answer. The first is the return. Over 33 years, 7% multiplies money by 9.3 and 5% multiplies it by 5.0, so the same $3,978,503 target needs $426,634 at the first rate and $795,193 at the second — $368,560 more from two percentage points. No other input moves the answer that far, which is the honest caveat on a figure printed to the dollar. The second is the inflation field, and it is the one that produces genuinely wrong pages rather than merely uncertain ones. It sits under Advanced options and opens at 0, which is a coherent state: at zero the return above is read as a REAL, after-inflation rate and every figure on the page is in today's money. The problem is the reader who types 7% meaning the usual nominal long-run figure and leaves inflation blank. Same inputs, two different pages: with 3% inflation the target is $3,978,503 and the coast number is $426,634, so $250,000 leaves a $176,634 gap; with inflation at 0 the target stays $1,500,000, the coast number falls to $160,852, and the page congratulates the same reader on being $89,148 past it. Pick a convention and hold it — nominal return with an inflation figure, or real return with inflation at zero — and never mix them. The third assumption is smaller but not small: the withdrawal rate that turns spending into a target. $60,000 at 4% is $1,500,000; the same spending at 3.5% is $1,714,286. Coasting has one genuine advantage here over most FIRE arithmetic, which is that it lands you at a traditional retirement age. The 4% figure comes from work on 30-year retirements, so it fits a 65-year-old far better than it fits a 45-year-old with fifty years to fund.
The contribution that is almost never worth stopping
There is one exception to the whole idea, and it is the employer match. A dollar-for-dollar match is an immediate 100% return on the dollars you defer, and no market assumption on this page comes anywhere near it — so a household that reaches its coast number almost always keeps deferring to the full match and redirects only what sits above it. Coasting is a decision about your own money, not about theirs. A second contribution worth keeping is the HSA, if you have a qualifying plan: contributions are deductible, growth is untaxed and qualified withdrawals are untaxed, which is a combination no retirement account offers, and after 65 the money can be drawn for anything at ordinary rates like a traditional IRA. Beyond those two, the freed cash flow has somewhere useful to go even for people who do not want to spend it. A taxable brokerage account is the most flexible destination, because it is the one pot reachable at any age without a penalty or a five-year wait — which makes it the raw material for retiring before 65 rather than at it, and turns a coast plan into an early-retirement plan later on. Finally, be clear about what this page leaves out, all of it in the same direction. Social Security is not here, and for a median earner it replaces a meaningful share of spending, which reduces what the portfolio has to fund. Neither is a pension, an inheritance, or a mortgage that is paid off before retirement — and a household whose housing cost drops by $20,000 a year at 62 needs $500,000 less at 4%. What is also missing runs the other way: tax on the way out, the order the returns arrive in rather than their average, and the possibility of a decade that simply does not deliver 7%. The number is a compass bearing, not a coordinate.
Frequently asked questions
What is Coast FIRE?
The point where the money already invested will compound into your full retirement number on its own, with nothing further added. You still work and still pay for your life out of what you earn — you simply stop feeding the retirement account. It is not early retirement and it is not financial independence. It is the end of the saving phase, which usually arrives ten to twenty-five years before the end of the working phase.
Why is the coast number so much smaller than my FIRE number?
Because compounding does the rest of the work and it is given decades to do it. At the figures this page opens with, $1,500,000 in today's money grows to $3,978,503 by 65 once 3% inflation is applied — and discounting that back 33 years at a 7% return leaves $426,634. The gap between $426,634 and $3,978,503 is not a rounding difference; it is thirty-three years of 7%, which multiplies money by 9.3. That multiple is also the reason the number is so sensitive to the return you assume: drop 7% to 5% and the coast number is $795,193.
Why does my coast number keep going up?
Because it is a discount, and the thing being discounted gets closer every year. At 32 you have 33 years of compounding left to do the work, so the requirement is $426,634. At 33 you have 32 years, so it is $456,498 — $29,864 more for waiting a single year. If inflation is switched on, the target at the far end climbs too. The requirement rising is normal and the schedule on the page shows it explicitly; what matters is whether your balance is rising faster, which is exactly what the two lines on the chart are for.
Should I actually stop contributing when I get there?
Rarely all of it, and almost never the employer match. A match is an immediate return on the dollars you defer that no market assumption comes close to, so most households that reach the coast number keep deferring to the full match and redirect only what sits above it. The other reason to keep going is that the coast number is a single-path projection: hit it in a year the market is expensive and a 30% fall the following year moves your coast date, not just your balance. Coasting is best treated as permission to earn less or spend more, not as an instruction to stop.
What return and inflation should I put in?
Whatever you use, use one convention consistently. If you enter a nominal return — 7% is the usual long-run figure quoted for a US stock-heavy portfolio before inflation — then you must also enter an inflation figure, or the page treats that 7% as real and the target it computes is far too small. If you prefer to work entirely in today's money, put your real return in the return field (roughly nominal minus inflation) and leave inflation at 0. Both are correct. Mixing them is the single most common way this calculation goes wrong, which is why the inflation field's own label says so.
What is the difference between Coast FIRE and Barista FIRE?
They stop opposite halves of the same job. Coasting keeps the career and the salary and stops the saving — you carry on covering all your own costs, including health coverage through work, until traditional retirement age. Barista FIRE stops the career and keeps a smaller paycheck that covers part of the spending, with the portfolio covering the rest, which needs a much larger balance than a coast number but arrives before retirement age. In the United States the deciding factor between them is usually health insurance rather than the wages.