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Coast FIRE Calculator

The amount you need invested today to stop saving entirely and still retire on time, plus whether you are already there and what age you reach it at.

Coast FIRE Calculator: with the default inputs, coast fire number is $226,613.

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Try an example
Coast FIRE number
$226,613

Invested today, this grows to your FIRE number by your retirement age with nothing more added.

Where you stand
Not yet. $126,613 short of coasting.
Still needed today
$126,613
Age you reach it
46
FIRE number at retirement
$1,250,000
Progress to coasting
0.4%
Spending your portfolio would cover today
$22,064
Assumptions
  • Returns are real, after inflation, and constant every year. Real markets are neither, and a bad sequence early does more damage than the average suggests.
  • Spending is in today's money and stays level in real terms through retirement.
  • No taxes, fees or account types are modelled; put retirement spending in gross terms to include the tax you will owe.
  • The withdrawal rate is applied to the portfolio at retirement; 4% comes from studies of 30-year US retirements and is less safe over longer ones.
The coast number falls the earlier you start
$0$500k$1.0M2032445665Age you stop saving
Coast FIRE numberInvested now
If your real return is not what you assumed
Real returnCoast number todayAgainst your portfolio
3%$444,229-$344,229
4%$316,769-$216,769
5%$226,613-$126,613
6%$162,632-$62,632
7%$117,079-$17,079
Math verified by automated testsUpdated 2026-09-112 sources cited

How this is worked out

The formula

FIRE number = annual spending the portfolio must cover ÷ withdrawal rate
Coast FIRE number = FIRE number ÷ (1 + real return)^(years until retirement)

Barista FIRE is the same sum with part-time income subtracted from the spending first.

Open How it’s calculated above to see this worked through with your own numbers.

What you enter

Your age now
A number.from 10 to 90 · whole numbers only · defaults to 30
Age you want to retire
A number.from 20 to 100 · whole numbers only · defaults to 65
Annual spending in retirement
In today's money. Include the taxes and health cover you will be paying yourself.in dollars · 0 or more · defaults to 50000
Invested now
Retirement accounts and taxable investments. Not your house, not cash you will spend.in dollars · 0 or more · defaults to 100000
Expected real return
After inflation, because the spending figure above is in today's money. US stocks have returned about 7% real long run; 4-5% is the cautious plan.a percentage · from -5 to 15 · defaults to 5
Withdrawal rate in retirement
4% is the classic rule for a 30-year retirement. 3-3.5% is the usual choice for a longer one.a percentage · from 0.5 to 20 · defaults to 4
Part-time income in retirement(under More options)
Set this above zero for Barista FIRE: the portfolio only has to cover what this does not.in dollars · 0 or more · defaults to 0
Still saving each year(under More options)
Used only to work out when you would reach the coast number if you keep saving.in dollars · 0 or more · defaults to 12000

What you get back

Coast FIRE numbermain answer
Invested today, this grows to your FIRE number by your retirement age with nothing more added.
Where you stand
Still needed today
Age you reach it
If you carry on saving at the rate above.
FIRE number at retirement
What the portfolio has to be worth when you stop: spending ÷ withdrawal rate.
Progress to coasting
Spending your portfolio would cover today
If you stopped saving right now and let it grow.

What this assumes

  • Returns are real, after inflation, and constant every year. Real markets are neither, and a bad sequence early does more damage than the average suggests.
  • Spending is in today's money and stays level in real terms through retirement.
  • No taxes, fees or account types are modelled; put retirement spending in gross terms to include the tax you will owe.
  • The withdrawal rate is applied to the portfolio at retirement; 4% comes from studies of 30-year US retirements and is less safe over longer ones.

About this calculator

Coast FIRE is the point where you can stop putting money in. Not stop working — stop saving. Your existing investments, left alone, grow to your retirement number on their own, and your job only has to cover this month's bills from here on.

The arithmetic

Two steps. Work out what the portfolio must be worth on the day you retire: annual spending divided by the withdrawal rate, so $50,000 a year at 4% means $1,250,000. Then discount that back to today at your expected real return. At 5% over 35 years the growth factor is about 5.5, so the coast number is around $227,000 — a fifth of the target, because the other four fifths are compounding you have not done yet.

That gap between $227,000 and $1,250,000 is the entire argument for investing early. It is also why the number is so unforgiving of a late start: the same sum at 45 rather than 30 needs about $471,000, because fifteen fewer years of compounding roughly doubles what you must already have.

Where this number is fragile

Everything rests on the real return you type in, compounded over decades, and that is the one input nobody knows. A single percentage point is not a rounding error here — over 35 years it moves the coast number by nearly 30%, from about $227,000 at 5% to about $163,000 at 6%. The table below runs your figure two points either way so you can see the spread rather than a false single answer.

Two more things the formula cannot see. Sequence-of-returns risk means a bad decade early does more damage than the average return suggests. And the 4% rule came from a study of 30-year US retirements starting in the twentieth century; for a retirement that might run 45 years, most people planning this way use 3 to 3.5% instead, which raises the target by a quarter or more.

Coast FIRE and Barista FIRE

They are the same calculation. Barista FIRE assumes you keep earning something in retirement — the name comes from taking a part-time job for the health insurance — so the portfolio only has to cover the gap. Put that income in the advanced field and the target falls by the same multiple: $20,000 of part-time income against $50,000 of spending cuts the portfolio's job by 40%, and the coast number with it.

What this does not tell you

Whether you should stop saving. Reaching the coast number means the plan works if the return holds, and it removes your margin for a bad decade, a job loss, or wanting to retire earlier than planned. Most people who reach it keep saving something. What it really buys is the freedom to take the worse-paid job you would rather do.

Frequently asked questions

What is Coast FIRE?

The amount you need invested now so that compound growth alone carries it to your retirement number, with nothing further added. You keep working to cover today's costs, but you stop contributing.

How is it different from FIRE?

FIRE is the portfolio that lets you stop working. Coast FIRE is the smaller, earlier milestone that lets you stop saving. At a 5% real return over 35 years the coast number is about a fifth of the FIRE number.

What return should I use?

It has to be a real return, after inflation, because the spending figure is in today's money. US stocks have returned roughly 7% real over the long run, but plans are usually built on 4-5% to leave room for a worse outcome. Try the table: the answer moves a lot.

What is Barista FIRE?

Coast FIRE with a part-time job in retirement, named for taking a coffee-shop role for the health insurance. The portfolio only funds the spending the job does not, so the target falls in proportion.

Should I actually stop saving once I get there?

That is a judgement, not a calculation. Hitting the number means the plan works if the return holds, and it spends the margin you were carrying. Most people treat it as permission to take a job they prefer rather than as a reason to stop investing.

Does this account for taxes?

Only if you build them in. Put your retirement spending in gross terms — what you will actually need to withdraw, including the tax you will owe on it — and the answer accounts for them. The calculator does not model account types or tax brackets.

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