Coast FIRE calculator

How much do you need invested before growth can do the rest? Find your Coast FIRE number, the age you reach it, and what part-time work changes. Then see how often it held up in real market history since 1928.

Market and inflation data through Dec 2025 · Every number is in today’s dollars · Updated · How it works

Try a starting point:

You today

Your goal

Use today’s prices. Every number on this page is in today’s dollars.

This rate is an example, not a forecast. Tap a past average to try it:

Past averages a year after inflation, 1928 to 2025 (NYU Stern returns, US CPI). Not a forecast.

The share of your savings you take out each year. 4% means 25 times your yearly spending.

Part-time work (Barista FIRE)

Add the cost of health insurance if your part-time job has none.

Other income (optional)

A start age below your retirement age counts as your retirement age.

History test

This sets the mix for the history test. What is not in stocks sits in 10-year Treasuries.

Your Coast FIRE number today

$244,742

You need $244,742 invested today to coast to $1,350,000 by 65. At $1,500 a month, your balance gets there at age 40 and 3 months, at a steady 5%.

You have $100,000. That is 41% of the way, with $144,742 to go.

40 and 3 monthsCoast FIRE age, adding $1,500 a month. Balance then: $404,766.
$1,350,000FIRE number: 25 × $54,000 a year
$551,602At 65 if you stop adding today. That backs $1,839 a month at 4%.
$2,221,070At 65 if you never stop adding
$648,286Barista FIRE number today, with $2,500 a month of pay
50 and 9 monthsEarliest part-time age at your pace. Barista FIRE number then: $920,547.
Age 30Age 48Age 65
If you keep addingCoast FIRE number neededIf you stop todayFIRE number9 in 10 real histories of the tested amount

Your balance crosses the Coast line at 40 and 3 months. After that, growth alone reaches $1,350,000 by 65, at a steady 5%.

History test

Your Coast FIRE number, $244,742, left alone for 35 years reached $1,350,000 in 35 of 64 real stretches (55%).

60% stocks, the rest in 10-year Treasuries, after inflation. Start years 1928 to 1991. Data through 2025: NYU Stern returns and US CPI. Past results, not a forecast.

$729,565Worst start, 1946
$1,400,227Middle result
$352,629Amount that reached it in 9 of 10 past stretches

Barista test: $648,286, paying a $2,000 monthly gap, reached $1,350,000 in 29 of 64 stretches. It ran out before 65 in 1.Same start years, mix and data as the test above. Past results, not a forecast.

What to add each month to coast by a set age

To coast by ageAdd each monthTotal deposits
35$2,713$162,783
40$1,521$182,540
45$1,132$203,696
50$943$226,208

At a steady 5% a year after inflation. An example rate, not a forecast.

One point lower or higher

Growth a year4%5% (yours)6%
Coast FIRE number today$342,111$244,742$175,642
Coast FIRE age49 and 1 month40 and 3 months34 and 10 months
Earliest part-time age57 and 0 months50 and 9 months45 and 10 months

Each column is a steady example rate after inflation, not a forecast.

Save my plan

Hypothetical illustration based on your inputs. Not a prediction, a recommendation, or the performance of any Amaltash strategy.

How it works: your Coast and Barista numbers come from the one steady growth rate you type, after inflation. The history test uses real yearly returns instead. They are the S&P 500 and 10-year Treasuries (NYU Stern, 1928–2025), less each year’s inflation (US CPI). Every amount is in today’s dollars.

Results change each time you change an input, and as new market data is added.

Real investing is different. Fees, taxes and trading costs are not included. Past market returns do not predict future returns, and you can lose money.

See every year

One row per year of age. “Coasting” marks the years your balance is at or above the Coast FIRE number.

AgeCoast FIRE number neededIf you keep addingIf you stop todayBarista FIRE numberStatus
30$244,742$100,000$100,000$648,286
31$256,979$123,484$105,000$656,056
32$269,828$148,142$110,250$664,213
33$283,319$174,033$115,763$672,779
34$297,485$201,218$121,551$681,773
35$312,360$229,763$127,628$691,216
36$327,978$259,735$134,010$701,132
37$344,376$291,206$140,710$711,543
38$361,595$324,250$147,746$722,475
39$379,675$358,946$155,133$733,954
40$398,659$395,378$162,889$746,006
41$418,592$433,630$171,034$758,661Coasting
42$439,521$473,796$179,586$771,949Coasting
43$461,497$515,969$188,565$785,902Coasting
44$484,572$560,252$197,993$800,551Coasting
45$508,801$606,748$207,893$815,934Coasting
46$534,241$655,569$218,287$832,085Coasting
47$560,953$706,832$229,202$849,045Coasting
48$589,001$760,657$240,662$866,852Coasting
49$618,451$817,174$252,695$885,549Coasting
50$649,373$876,516$265,330$905,181Coasting
51$681,842$938,826$278,596$925,795Coasting
52$715,934$1,004,251$292,526$947,440Coasting
53$751,731$1,072,948$307,152$970,167Coasting
54$789,317$1,145,079$322,510$994,030Coasting
55$828,783$1,220,817$338,635$1,019,086Coasting
56$870,222$1,300,342$355,567$1,045,395Coasting
57$913,733$1,383,842$373,346$1,073,020Coasting
58$959,420$1,471,518$392,013$1,102,026Coasting
59$1,007,391$1,563,578$411,614$1,132,482Coasting
60$1,057,760$1,660,241$432,194$1,164,461Coasting
61$1,110,648$1,761,737$453,804$1,198,039Coasting
62$1,166,181$1,868,308$476,494$1,233,296Coasting
63$1,224,490$1,980,207$500,319$1,270,315Coasting
64$1,285,714$2,097,701$525,335$1,309,186Coasting
65$1,350,000$2,221,070$551,602$1,350,000Coasting

What is Coast FIRE?

Coast FIRE means you have enough invested that growth alone can reach your goal. From then on, new deposits are a choice. Your job only has to pay today’s bills. FIRE is short for two things: financial independence, and retire early. Your Coast FIRE number is the amount that gets you there.

  • What changes: the math no longer needs new deposits.
  • What stays the same: you still work, and your pay still covers your bills.
  • What can undo it: weak markets, or spending more than you planned.

The growth comes from compounding. That means you earn growth on your past growth, not only on the money you put in.

The goal is your FIRE number. That is the savings that could pay for your spending once you stop work.

Work out your FIRE number in the FIRE calculator →

How do I calculate my Coast FIRE number?

Divide your FIRE number by the growth your money can earn before you retire. Say you will spend $54,000 a year. At a 4% withdrawal rate, your FIRE number is $1,350,000. At a steady 5% a year after inflation for 35 years, your Coast FIRE number is $244,742. The 5% is only an example.

  1. Add up what you will spend in a year. Here that is $54,000.
  2. Divide it by your withdrawal rate. $54,000 ÷ 0.04 = $1,350,000. That is your FIRE number.
  3. Count the years until you retire. From 30 to 65 is 35 years.
  4. Grow $1 for that many years. At 5% a year, $1 becomes about $5.52.
  5. Divide your FIRE number by that growth. The answer is $244,742.

Find what you spend each month with the budget calculator →

F=12 SwF = \frac{12\,S}{w}

In words: Multiply your monthly spending by 12. Then divide by your withdrawal rate.

FF
your FIRE number
SS
what you will spend each month in retirement
ww
your withdrawal rate, as a decimal (4% is 0.04)
C=F(1+r)nC = \frac{F}{(1+r)^{n}}

In words: Take your FIRE number. Divide it by one plus the growth rate, once for each year until you retire.

CC
your Coast FIRE number
FF
your FIRE number
rr
growth each year after inflation, as a decimal
nn
the years until you retire

A withdrawal rate is the share of your savings you take out each year. A 4% rate is the same as saving 25 times your yearly spending.

Test how long your money lasts once you take it out, in the retirement calculator →

Coast FIRE number by age

The younger you are, the less you need, because your money has more years to grow. Say you want to spend $60,000 a year from age 65. At a steady 5% a year after inflation, a 30-year-old needs $271,935 invested. A 40-year-old needs $442,954, and a 50-year-old needs $721,526. These are examples, not forecasts.

Age nowYears to growSpend $40,000 a year$60,000 a year$80,000 a year$100,000 a year
FIRE number$1,000,000$1,500,000$2,000,000$2,500,000
2540$142,046$213,069$284,091$355,114
3035$181,290$271,935$362,581$453,226
3530$231,377$347,066$462,755$578,444
4025$295,303$442,954$590,606$738,257
4520$376,889$565,334$753,779$942,224
5015$481,017$721,526$962,034$1,202,543
5510$613,913$920,870$1,227,827$1,534,783
605$783,526$1,175,289$1,567,052$1,958,815

The table assumes you retire at 65 with a 4% withdrawal rate. Growth is a steady 5% a year after inflation. Each 5 years of waiting adds about 28% to the number.

Do you spend a different amount? The numbers scale. Spending $50,000 a year needs half of the $100,000 column.

What growth rate should I use?

Use a rate after inflation, so every number stays in today’s dollars. From 1928 to 2025, the S&P 500 grew 6.8% a year after inflation. A mix of 60% stocks and 40% bonds grew 5.2%. Those are past results (NYU Stern, US CPI), not a forecast. Try a lower rate too.

Inflation is a general rise in prices. It cuts what each dollar can buy. The averages above use NYU Stern return data, with US inflation taken out.

Years to grow3% a year4% a year5% a year6% a year7% a year
10$744,094$675,564$613,913$558,395$508,349
15$641,862$555,265$481,017$417,265$362,446
20$553,676$456,387$376,889$311,805$258,419
25$477,606$375,117$295,303$232,999$184,249
30$411,987$308,319$231,377$174,110$131,367
35$355,383$253,415$181,290$130,105$93,663
40$306,557$208,289$142,046$97,222$66,780

Each cell is the Coast FIRE number for a $1,000,000 FIRE number, at a steady example rate. Over 35 years, one point less growth raises the number by about 40%.

Your mix matters too. The right mix of stocks and bonds depends on two things. They are how many years you have and how much risk you can take. Fees also lower growth: a 0.5% yearly fee turns 5% into about 4.5%.

Try other growth rates and fees in the investment calculator →

Look up S&P 500 returns from any start year in the S&P 500 calculator →

Is Coast FIRE realistic? What real history shows

We left money alone for 35 years in each real stretch from 1928 to 2025. The mix was 60% stocks and 40% bonds, after inflation. A Coast number built on a steady 5% reached its goal in 35 of 64 stretches. These are past results (NYU Stern returns, US CPI), not a forecast.

That is a little over half. Reaching the goal in 9 of 10 stretches took 44% more money. The table shows what $1 became in that same mix. These are also past results for 1928 to 2025 (NYU Stern returns, US CPI), not a forecast.

Years left aloneStretchesWorst (start year)9 of 10 did at leastMiddleBest (start year)
10890.76x (1972)0.95x1.66x3.13x (1989)
20790.98x (1962)1.37x2.83x7.05x (1980)
30692.38x (1955)2.86x4.87x8.78x (1982)
35642.98x (1946)3.83x5.72x12.85x (1982)
40593.46x (1940)4.22x6.75x20.18x (1982)

The table’s numbers are after inflation. Short stretches were the risky ones. Over 10 years, the worst start lost about a quarter.

Gy=∏j=0n−11+a sy+j+(1−a) by+j1+πy+jG_{y} = \prod_{j=0}^{n-1} \frac{1 + a\,s_{y+j} + (1-a)\,b_{y+j}}{1 + \pi_{y+j}}

In words: For each year, take the return of your mix and take out inflation. Then multiply the years together.

GyG_{y}
what $1 became, starting in year y
aa
the share in stocks
sy+js_{y+j}
the S&P 500 return in that year
by+jb_{y+j}
the 10-year Treasury return in that year
πy+j\pi_{y+j}
inflation in that year
nn
the years the money is left alone

Many calculators use 7% a year after inflation. Over real 30-year stretches from 1928 to 2025, the S&P 500 alone did that in 40 of 69. A 60/40 mix did it in 6 of 69. Again, these are past results (NYU Stern returns, US CPI), not a forecast.

See how a plan held up in real history, in the retirement calculator →

At what age can I Coast FIRE?

You reach Coast FIRE when your balance catches the Coast number for your age. Start with $100,000 at 30 and add $1,500 a month. At a steady 5% a year after inflation, your balance catches it at age 40 and 3 months. It is about $404,766 by then. The rate is only an example.

To coast by ageAdd each monthTotal deposits
35$2,713$162,783
40$1,521$182,540
45$1,132$203,696
50$943$226,208

The table uses the same plan: $100,000 at 30, and a goal of $1,350,000 at 65. Coasting 5 years sooner costs far more each month than 5 years later saves.

m∗=12n−ln⁡(G−D gM (1+g))ln⁡(1+g)m^{*} = 12n - \frac{\ln\left(G - \dfrac{D\,g}{M\,(1+g)}\right)}{\ln(1+g)}

In words: First find how far short you would be if you stopped today. The formula then finds the month your deposits close that gap.

m∗m^{*}
the months until you reach Coast FIRE, rounded up
nn
the years until you retire
GG
what $1 grows to by the time you retire
DD
how far short you would be at retirement if you stopped adding today
MM
what you add each month
gg
growth for one month, worked out from the yearly rate
Mx=D g(1+g)[G−(1+g)12 (R−x)]M_{x} = \frac{D\,g}{(1+g)\left[G - (1+g)^{12\,(R-x)}\right]}

In words: Take the gap you would have at retirement. Divide it by what $1 a month would grow to, if you added it until that age.

MxM_{x}
the monthly deposit that gets you to Coast FIRE by age x
DD
how far short you would be at retirement if you stopped adding today
gg
growth for one month, worked out from the yearly rate
GG
what $1 grows to by the time you retire
RR
the age you retire
xx
the age you want to coast by

Waiting has a price. At 5%, the number you need rises 5% each year. It doubles in about 14 years.

Find how long money takes to double with the rule of 72 calculator →

Are your deposits too small to get there? The calculator shows the monthly amount that would work.

What is Barista FIRE, and what is my Barista FIRE number?

Barista FIRE means part-time pay covers some of your bills. Your investments cover the rest until you retire. Your Barista FIRE number is your Coast FIRE number plus the cost of the gap years. If your pay covers every bill, the two numbers are the same.

Go part-time atPay $1,500 a monthPay $2,500Pay $3,500Pay $4,500
40$919,680$746,006$572,332$398,659
45$969,500$815,934$662,367$508,801
50$1,033,086$905,181$777,277$649,373
55$1,114,238$1,019,086$923,935$828,783

The table uses $4,500 a month of spending and a goal of $1,350,000 at 65. The rate is a steady 5%. The last column is plain Coast FIRE: the pay covers every bill.

Take age 45 with $2,500 of pay. The gap is $2,000 a month for 20 years. The Barista FIRE number is $815,934. That is the $508,801 Coast number plus $307,133 for the gap years.

As a plain sum, that gap adds up to $480,000. Growth pays the other $172,867.

Bk=min⁡(T, F(1+g)k+q (1+g) 1−(1+g)−kg)B_{k} = \min\left(T,\ \frac{F}{(1+g)^{k}} + q\,(1+g)\,\frac{1-(1+g)^{-k}}{g}\right)

In words: Take the Coast FIRE number for that month. Add the money that pays your gap each month until you retire. The answer is capped at what you would need to stop work today.

BkB_{k}
your Barista FIRE number with k months left
TT
what you would need to stop work today (your FIRE number, if you have no other income)
FF
your FIRE number
qq
your gap each month: what you spend while part-time, less your pay (never below zero)
gg
growth for one month, worked out from the yearly rate
kk
the months until you retire

Many tools use a shortcut: spending minus pay, divided by 4%. Here that gives $600,000. It assumes the pay never stops.

We also ran the age 45 plan through real history, in a 60/40 mix. It reached the goal in 42 of 79 stretches and never ran out. These are past results for 1928 to 2025 (NYU Stern returns, US CPI), not a forecast. Taking money out in weak years hurts more than a steady rate shows.

Coast FIRE vs Barista FIRE vs FIRE

All three aim at the same FIRE number. With FIRE, you stop work once you have it. With Coast FIRE, you could stop adding early and keep working while growth does the rest. With Barista FIRE, you also cut your hours, and your investments pay part of your bills.

PlanWho pays today’s billsNew depositsNumber in our example, at 30
Coast FIREYour full payA choice$244,742
Barista FIREPart-time pay plus investmentsNone$648,286
FIREInvestmentsNone$1,350,000

The example is the plan from above: spend $4,500 a month, retire at 65, a steady 5%. The Barista row uses $2,500 a month of part-time pay.

Lean FIRE and Fat FIRE are the same idea with a smaller or a bigger budget.

Compare Lean FIRE and Fat FIRE numbers in the FIRE calculator →

Does Coast FIRE include Social Security, a pension or my 401(k)?

Count money invested for later: a 401(k), an IRA and other investment accounts. Leave out your home, because you live in it. Social Security or a pension means you need less. Enter it as other income, with the age it starts. Low pay in part-time years can shrink your Social Security check.

Say you spend $4,500 a month and retire at 60. You expect $2,000 a month from age 67. The gap that lasts is $2,500 a month, which needs $750,000. The 7 years before 67 need $168,000 more. So your FIRE number is $918,000, not $1,350,000.

F=12 max⁡(0, S−I)w+12 min⁡(S, I) min⁡(A−R, 1w)F = \frac{12\,\max(0,\ S - I)}{w} + 12\,\min(S,\ I)\,\min\left(A - R,\ \frac{1}{w}\right)

In words: Size the gap that lasts: spending minus other income, divided by your withdrawal rate. Then add the years before that income starts, as a plain sum.

FF
your FIRE number
SS
what you will spend each month in retirement
II
other income you get each month, like Social Security
ww
your withdrawal rate, as a decimal (4% is 0.04)
AA
the age that income starts, never before the age you retire
RR
the age you retire
  • Social Security is based on your highest 35 years of pay. Years of low pay can pull it down.
  • Money taken from a 401(k) or IRA before age 59½ usually owes a 10% extra tax.
  • If you stop your deposits, you can give up money your employer adds, called a match.
  • Taxes shrink it too. As an example, $1,350,000 in a traditional 401(k), taxed at 22%, leaves $1,053,000.

This guide teaches the basics. It is not tax advice.

Add up what counts as invested money in the net worth calculator →

Barista FIRE and health insurance

Health cover is the cost people miss. Employers do not have to cover part-time workers, even when they cover full-time ones. If your part-time job has no plan, you can buy one on the Health Insurance Marketplace. A tax credit can lower the price, based on your income. Medicare starts at 65.

  1. Ask if the part-time job comes with a health plan.
  2. If it does not, price a Marketplace plan for your household.
  3. Add the monthly cost to “You spend each month while part-time” in the calculator.

The tax credit depends on your household size and the income you expect. If you retire before 65 and lose a job plan, the Marketplace is open to you too.

Coast FIRE formula for Excel or Google Sheets

One formula does it. Put your FIRE number in cell A1 and your growth rate in A2. Put the years until you retire in A3. Then type =A1/(1+A2)^A3. With 1,350,000, 5% and 35, the sheet shows 244,741.89. The built-in function =PV(A2,A3,0,-A1) gives the same answer.

  1. In A1, type your FIRE number: 1350000.
  2. In A2, type your growth rate after inflation: 5%.
  3. In A3, type the years until you retire: 35.
  4. In A4, type =A1/(1+A2)^A3 and press Enter.

Do you want every year? Open “See every year” below the tool, then tap Download CSV. The file opens in Excel or Google Sheets.

Check what a balance is worth later in the future value calculator →

What are the risks of Coast FIRE?

Coast FIRE leans on growth you cannot control. Three things can push the goal away: weak markets, spending that grows, and stopping work sooner than planned. In the worst real 10 years for a 60/40 mix, 1972 to 1981, money lost 24% after inflation. A past result (NYU Stern, US CPI), not a forecast.

Check your number once a year. This calculator keeps the math plain. Here is what it assumes or leaves out.

  • One steady rate. Real returns jump around from year to year.
  • No taxes and no fees. Both leave you with less.
  • Spending that never changes. Real budgets move.
  • A goal set by one rule. A 4% withdrawal rate is a rule of thumb, not a promise.

You can start adding again at any time. Extra deposits and a cash cushion both give you room.

Size your cash cushion with the emergency fund calculator →

See one deposit grow year by year in the compound interest calculator →

See what a cash cushion earns in the high-yield savings calculator →

How this calculator works

Today’s dollars. The growth rate is after inflation, so every number reads in today’s money. We assume your spending and your deposits rise with prices.

The steady-rate math. A deposit goes in at the start of each month. Growth is added in 12 equal steps a year. Your Coast FIRE number is your FIRE number divided by that growth.

The history test. We leave the tested amount alone through each real stretch of years since 1928. Each year uses the real S&P 500 and 10-year Treasury returns (NYU Stern) minus that year’s inflation (US CPI, FRED). The Barista test also takes your monthly gap out. These are past results, not a forecast.

Other income. Social Security or a pension lowers the amount you need. The years before it starts are added as a plain sum, with no growth.

What it leaves out. Fees, taxes, and changes to your spending or pay. Real returns also move from year to year, which one steady rate cannot show.

Questions people ask

How much do I need to Coast FIRE at 30?

It depends on your spending and your growth rate. Take age 30, with 35 years to grow at a steady 5% a year after inflation. You need $181,290 for each $1,000,000 of your FIRE number. For $60,000 a year of spending, that is $271,935. The 5% is an example, not a forecast.

Can I Coast FIRE with $500,000?

It depends on your age and your spending. Here is the plain math. $500,000 left alone for 20 years at a steady 5% a year after inflation becomes $1,326,649. At a 4% withdrawal rate, that backs $53,066 a year. With $300,000 and 25 years, it is $1,015,906, or $40,636 a year. The rate is an example.

Does Coast FIRE account for inflation?

Yes, if you use a growth rate after inflation, as this calculator does. Then your spending, your FIRE number and your Coast FIRE number all stay in today’s dollars. Do not mix a before-inflation rate with today’s spending. That makes the number look smaller than it is.

Should I stop my 401(k) when I reach Coast FIRE?

You do not have to. Some employers add money when you do, called a match, and stopping gives that up. A 4% match on $70,000 of pay is $2,800 a year. Extra deposits also give you a cushion if markets are weak. This is not tax advice.

How do I calculate Coast FIRE as a couple?

Treat the household as one plan. Add both partners’ invested balances, and use the spending you share. If you spend $5,500 a month together, that is $66,000 a year, or $1,650,000 at 25 times. For the years to grow, count to the year you both stop work.

Can I Coast FIRE with kids or a mortgage?

Yes, but both change your inputs. Kids raise spending for many years, so enter the higher number to leave room. A mortgage that ends before you retire lowers what you will spend later. Leave your home’s value out of the invested money.

What is Flamingo FIRE?

Flamingo FIRE is a kind of Coast FIRE. You save half of your FIRE number, then stop adding and work less while it grows. At a steady 5% a year after inflation, money doubles in about 14 years. So half becomes the full number in that time. The rate is an example.

Does reaching Coast FIRE mean I can retire?

No. Coast FIRE means the math no longer needs new deposits. You still need pay to cover your bills until the retirement age you set. To stop full-time work sooner, look at your Barista FIRE number above, or your full FIRE number.

More calculators

Retirement calculatorTest a plan against every stretch of market history since 1928.FIRE calculatorFind your FIRE number and how long past markets took to reach it.Net worth calculatorAdd up what you own and owe. See how you compare by age.Compound interest calculatorSee how interest earns interest at a fixed rate.Investment calculatorPick an amount, a time and a real past average rate. See how it could add up.Budget calculatorAdd up your pay and your spending. See what is left each month.

See this with your real accounts

Connect your accounts and we keep the numbers up to date for you.

Connect accounts

Reviewed by Tavish Sharma, CFA · Last reviewed

Published by Amaltash Advisors LLC, an SEC-registered investment adviser

Sources

Get started