Free Online FIRE Calculator

What the FIRE calculator shows

This FIRE calculator estimates when your investments could cover your living costs for good. FIRE stands for financial independence, retire early: you save a large share of your income, invest it, and stop depending on a paycheck once the portfolio is big enough to fund your spending through withdrawals.

You enter your age, your income after tax, your annual expenses, what you have invested today, an expected annual return and a safe withdrawal rate. The calculator turns those into four answers: your FIRE number (the portfolio you need), Years to FIRE, your FIRE age and your Savings rate. It also shows the Lean, Standard, Fat and Coast FIRE targets, a chart of the whole journey and a year-by-year table that continues into the withdrawal years.

It is a planning tool, not a forecast. It assumes a steady return every year, so it cannot show a market crash, and it does not know about taxes, pensions or Social Security. Everything runs in your browser, and nothing you enter is sent anywhere.

In this guide:

• How to fill in every field and read the results, the chart and the table
• The formulas behind the FIRE number, Years to FIRE and Coast FIRE
• What the 4% rule is, where it comes from and how the calculator uses it
• Why savings rate matters most, and how Lean, Fat, Coast and Barista FIRE differ
• How long the money lasts, three worked examples in US dollars and common mistakes

If investing itself is new to you, start with what investing is.

How to use the FIRE calculator

The calculator opens in US dollars with an age of 30, an income of $80,000, expenses of $50,000 and a portfolio of $50,000. The examples in this guide keep USD. On wide screens the UAH / USD / EUR switch sits in the header of the Your numbers panel; on phones and tablets it is under More options. Only the symbol and formatting change; nothing is converted.

The six inputs in the table below each have a number box and a slider. The money sliders run to 200,000 for income and expenses and to 1,000,000 for the portfolio in USD or EUR, and twenty times that in UAH; larger values can be typed. The return slider covers 0% to 15%, and you can type up to 30%. The Conservative, Moderate and Aggressive chips under it set 5%, 8% or 11%.

More options is collapsed at first and holds six more controls, without sliders:

A value outside a range is pulled back to the limit when you leave the field, and ages and years are rounded to whole numbers. On phones, income, expenses and the portfolio use − and + buttons instead of a slider, in steps of 2,000, 2,000 and 10,000 in USD or EUR, and twenty times that in UAH.

Reading the results

On wide screens the results stay in view to the right of the inputs. The headline is Years to FIRE. If your portfolio already covers the FIRE number, it reads Already there and a note confirms it. If the target is not reached within 100 years, it reads More than 100 years and a note suggests what to change. Three figures follow: FIRE age (a dash when FIRE is out of reach), FIRE number and Savings rate.

Three tabs show the detail. Chart plots Portfolio value and Total contributions (your starting portfolio plus everything saved) by age, with the FIRE number as a green dotted line and the Lean FIRE and Fat FIRE targets as lighter and darker grey dotted lines. Year by year lists Age, Phase, Portfolio, Contributions, Withdrawals and Growth for each year, first in the Accumulation phase and then in the Withdrawal phase. Variants lists Lean FIRE, Standard FIRE (highlighted), Fat FIRE and Coast FIRE with their amounts.

With the defaults, the headline shows 18 years, with a FIRE age of 48, a FIRE number of $1,250,000 and a Savings rate of 37.5%.

Pin to compare keeps the current inputs as a reference. The headline then shows the change, such as +4 years vs pinned when you pin the defaults and click Conservative, the chart adds the pinned portfolio as a dashed line, and a caption lists the pinned scenario. Switching the currency, Reset or a reload clears it. PDF exports the inputs, the four results and the yearly table, without the pinned scenario. Share shares a link to the page without your numbers, and Reset, the round-arrow button on wide screens, restores the defaults, including US dollars. On phones and tablets, the results sit in a bar fixed to the bottom of the screen; Details opens the figures, the notes, the tabs and the buttons.

How the FIRE calculation works

The calculator works in whole years. It sets a target, grows your portfolio towards it and then runs the withdrawal years.

The FIRE number and its variants

FIRE number = E ÷ w
Lean FIRE = (E × Lean multiplier) ÷ w
Fat FIRE = (E × Fat multiplier) ÷ w
Savings = I − E
Savings rate = (I − E) ÷ I

• E is Annual expenses and I is Annual income (after tax)
• w is the Safe withdrawal rate as a decimal, so 4% is 0.04

Dividing by 0.04 is the same as multiplying by 25, which is where the "25 times expenses" rule of thumb comes from.

Years to FIRE

P(t) = P(t − 1) × (1 + r) + (I − E)
Years to FIRE = first year t in which P(t) ≥ FIRE number
FIRE age = Current age + Years to FIRE

• P(0) is Current portfolio value
• r is the yearly return used by the calculator (see below)

Each year the portfolio first grows by the return, then the year's savings are added at the end of the year. If income equals expenses, growth alone has to reach the target; if expenses are higher, the shortfall comes out of the portfolio, and a portfolio that runs out stays at $0. The search stops at 100 years; if the target is not reached by then, the headline reads More than 100 years.

Real return and Coast FIRE

r = (1 + R) ÷ (1 + π) − 1   (box checked)
r = R   (box unchecked)
Coast FIRE = FIRE number ÷ (1 + r) ^ (T − A)

• R is Expected annual return and π is Expected inflation rate
• T is Traditional retirement age and A is Current age, with at least 1 year between them in the formula

The inflation-adjusted return is the exact one, not R minus π: 7% and 3% give 3.88%, not 4%.

The withdrawal phase

After the FIRE year, the table switches to the Withdrawal phase. Each year the portfolio grows by r, then the calculator withdraws FIRE number × w, which equals your annual expenses. The withdrawal is the same every year; with the box checked that is in today's money, so it keeps up with inflation. If the portfolio runs short, the last withdrawal takes what is left and later rows show $0. The projection runs for Post-FIRE projection years after FIRE, or, if FIRE is never reached, until the traditional retirement age plus that many years, capped at 100 years.

Assumptions behind the numbers

• A steady return. The same return applies every year, with no bad years or good years.
• Yearly steps. Growth comes first, then savings are added, or a shortfall or the withdrawal is taken, at the end of each year.
• Flat spending and income. Expenses and income never change, except through the inflation setting.
• No other income. Pensions, Social Security, part-time work and inheritances are not included.
• No taxes or fees. Income is already after tax, and withdrawals, gains and fund fees are not taxed or charged.

What is a FIRE number?

Your FIRE number is the portfolio at which a chosen withdrawal rate pays for your spending. The withdrawal rate is the lever: the lower it is, the more you need, but the longer the money should last. This table shows the calculator's FIRE number at five rates.

Moving from 4% to 3.5% raises the target by about 14%, and moving to 3% by a third.

The expenses you enter should be what you will spend after you stop working, not what you spend today. Commuting may disappear, while health insurance, travel or home repairs may cost more.

The 4% rule and safe withdrawal rates

The 4% rule comes from a 1994 article by financial planner William Bengen, Determining Withdrawal Rates Using Historical Data, published in the October 1994 issue of the Journal of Financial Planning. He tested a portfolio of 50% stocks and 50% intermediate-term Treasuries against US market history from 1926 onward, withdrawing a percentage of the starting value in the first year and then raising the dollar amount with inflation every year. His findings:

• A 4% first-year withdrawal never exhausted the portfolio in less than 33 years, and in most cases it lasted 50 years or longer.
• A 4.25% withdrawal could exhaust a portfolio in as little as 28 years.

In February 1998 the AAII Journal published Retirement Savings: Choosing a Withdrawal Rate That Is Sustainable by Philip Cooley, Carl Hubbard and Daniel Walz, often called the Trinity study. It tested withdrawal rates of 3% to 12% over 15 to 30 years, using S&P 500 and high-grade corporate bond returns for 1926 to 1995, without taxes or costs. With inflation-adjusted withdrawals, rates of 3% to 4% kept high success rates for stock-dominated portfolios, and the authors concluded that early retirees expecting long payout periods should plan on lower withdrawal rates.

How the calculator uses the rate

The calculator uses the safe withdrawal rate to size the target, not to test it. With a steady return, the money never runs out if the return is at least as high as the withdrawal rate. Real markets have bad sequences: a crash in the first years of retirement does far more damage than the same crash 20 years later, and a steady-rate model cannot show that. Use a rate you would be comfortable with after a bad decade, which for a retirement that could last 50 years usually means testing 3% to 3.5%.

How long will my money last?

The withdrawal phase of the table shows how long a portfolio lasts at a steady return. The table below starts at age 40 with a portfolio exactly equal to a $1,000,000 FIRE number, a 60-year post-FIRE projection and the inflation box unchecked, so read each return as a return after inflation. Each cell shows how many years pass before Portfolio first shows $0.

Two rules follow from the steady-return model. If the return equals the withdrawal rate, the portfolio stays exactly at the FIRE number: the 4% row ends at $1,000,000 after 60 years at a 4% return. If the return is below the withdrawal rate, the portfolio shrinks a little faster every year until it runs out. A 4% withdrawal with a 2% real return lasts 36 years, which is enough from 65 but not from 40.

Savings rate and years to FIRE

The savings rate is the share of your after-tax income you do not spend. It is the strongest lever in the calculator because it works twice: more money goes into the portfolio each year, and the FIRE number shrinks because it is based on lower expenses.

The table uses $80,000 a year after tax, no starting portfolio, age 30, a 5% return with the inflation box unchecked and a 4% withdrawal rate.

The income is the same in every row; only spending changes. Going from 10% to 20% takes 15 years off the timeline, and going from 50% to 60% another 4 years. When you start from zero, the years depend on the savings rate, not on the income level: someone earning twice as much with the same savings rate gets the same answer, because both the savings and the target double. For how money grows once it is invested, see compound interest and the time value of money.

Lean, Fat, Coast and Barista FIRE

Lean FIRE and Fat FIRE

Lean FIRE and Fat FIRE are the same calculation at different spending levels. Lean FIRE covers a minimal budget, and Fat FIRE a more comfortable one. The calculator multiplies your annual expenses by the multipliers under More options, 0.7x and 1.5x by default, and divides by the withdrawal rate.

Here is someone aged 35 with $90,000 of income after tax, $50,000 of expenses, a $100,000 portfolio, a 7% return and a 4% withdrawal rate. The last column is read from the year-by-year table: the first age at which Portfolio reaches the target.

A target 30% lower is reached only 3 years earlier here, because the portfolio grows fastest near the end. Lean FIRE leaves little room for surprises, so it suits people whose costs are genuinely low and stable.

Fat FIRE needs a different reading. Years to FIRE and the withdrawal phase are tied to the Standard number, so this table starts withdrawing $50,000 a year at age 50. To time a Fat target, raise Annual expenses to the Fat level, and your income too if savings should stay the same, then read Years to FIRE again.

Coast FIRE

Coast FIRE is the point at which you could stop saving for retirement altogether: the money already invested would grow to your FIRE number by your traditional retirement age with no further contributions. You still work, but only to pay your current costs. The calculator shows it as Coast FIRE in the Variants tab, using the formula above.

The table shows the Coast FIRE amount for a $1,000,000 FIRE number ($40,000 at 4%) and a traditional retirement age of 65.

Coast FIRE is very sensitive to the return. At age 30 the 7% figure is about half the 5% figure, and the last column shows what checking the inflation box does to the same 7%. Treat the inflation-adjusted figure as the honest one.

Barista FIRE

Barista FIRE sits between Coast and full FIRE: you leave full-time work once the portfolio covers part of your spending and a part-time job covers the rest. The calculator has no Barista figure, but the Lean FIRE multiplier can stand in for it. Set it to the share of expenses the portfolio must cover, and Lean FIRE in the Variants tab and its dotted line on the chart show the Barista target. Example 3 below does exactly that.

Nominal vs inflation-adjusted FIRE projections

The Show inflation-adjusted values box changes the return the calculator uses. Unchecked, the portfolio grows at the full expected return, while your expenses and FIRE number stay where you entered them. That quietly assumes prices never rise. Checked, the calculator uses the return after inflation, so the portfolio, contributions, withdrawals and targets are all in today's money.

Here is a 32-year-old with $85,000 of income after tax, $50,000 of expenses, $60,000 invested, a 7% expected return and a 4% withdrawal rate:

The FIRE number stays at $1,250,000 in every row, because it is in today's money. What changes is how quickly a real portfolio gets there. You can reach the same result by leaving the box unchecked and entering a return that is already after inflation. Either way, do not mix a nominal return with a target in today's money. The article on inflation and why money loses value explains the effect, and the inflation impact calculator shows what a future amount is worth today.

Retiring early in the US: age 59½ and Social Security

Two US rules shape any early retirement plan, and the calculator models neither of them.

The tax rules come from IRS Topic 558 (reviewed September 24, 2026) and the IRS page on substantially equal periodic payments (reviewed July 23, 2026), which names section 72(t). The ages come from 20 CFR 404.409, as current on October 15, 2026.

In practice, early retirees need money they can reach before 59½, such as a taxable brokerage account, or a plan for one of the exceptions. The calculator treats all your investments as one pot. Its Traditional retirement age of 65 only sets the Coast FIRE target and the table length when FIRE is not reached; you may want to set it to 67 if that is your full retirement age. Social Security is not added to the projection, so a plan that ignores it is conservative for the years after benefits start.

FIRE at a glance

This grid shows Years to FIRE for different savings rates and returns, starting with no portfolio, $80,000 of income after tax, a 4% withdrawal rate and the inflation box unchecked. Every value comes from the calculator.

Read across a row to see what the return does and down a column to see what the savings rate does. At a 10% savings rate, the gap between a 3% and a 9% return is 34 years; at 60% it is 3 years. The higher your savings rate, the less your plan depends on markets.

Worked examples

Each example uses USD and shows what the calculator returns.

Common mistakes with FIRE calculations

• Using today's spending instead of retirement spending. Health insurance, home repairs and travel often cost more without an employer. Enter the budget you will actually live on.
• Leaving the inflation box unchecked with a nominal return. That grows the portfolio at full speed towards a target that never rises with prices. Check the box or enter a return after inflation.
• Treating 4% as a guarantee. The classic studies covered retirements of up to about 30 years in US history. For a retirement that may last 50 years, test 3% to 3.5%.
• Forgetting taxes on withdrawals. The calculator withdraws exactly your expenses. If withdrawals will be taxed, add the tax to Annual expenses.
• Using pre-tax income. The field is income after tax. Gross pay overstates savings and shortens the timeline.
• Choosing the Aggressive chip for comfort. An 11% return cuts Example 1 from 17 years to 14, but the calculator cannot tell you how likely that return is.
• Ignoring fees. A fund fee lowers your return every year. Subtract it from Expected annual return; the fees drag calculator shows what it costs over decades.

Limitations and next steps

The FIRE calculator answers one question clearly: at a steady return, how big must your portfolio be, and how long will it take to get there at your current savings rate? It cannot model market crashes or the order of returns, changes in income or spending, taxes, fees, pensions, Social Security, health costs or the rules for reaching retirement accounts early.

Use it to see how savings rate, return and withdrawal rate trade off, then check the parts it leaves out:

• The investment goal calculator works out the monthly amount needed to reach a FIRE number by a chosen date.
• The compound interest calculator shows month-by-month growth of a portfolio with regular contributions.
• The passive income calculator estimates the income a portfolio can pay.
• The emergency fund calculator sizes the cash buffer that keeps a plan on track.

For background, read about types of investment assets and risk and return. For decisions about your own money, accounts or taxes, consider a qualified, independent financial adviser who can look at your full situation.