FIRE Calculator
Find your FIRE number and see how soon you can reach financial independence. Enter your current age and investments, your annual expenses, how much you invest each year, and an expected return — and this calculator shows the nest egg that makes work optional (your annual spending divided by a safe withdrawal rate, 25× at 4%) plus the years and age until you get there. See your Coast FIRE number, your savings rate, and a projection of your portfolio climbing to your FIRE number. Everything is in today's dollars, and you can share a link or export a PDF — no sign-up required.
Everything already invested toward financial independence.
How much you invest each year while building toward FI.
Optional — enter your income to see your savings rate.
Yearly spending your portfolio must cover, in today's dollars.
4% = 25× expenses
Real, inflation-adjusted (~5–7% typical).
Common withdrawal rates:
The age by which your current portfolio, left untouched, would coast to your FIRE number.
Advanced — most people should leave this off (real-return approach).
Quick examples:
Your FIRE Number & Timeline
FIRE Number
Time to FIRE
The Details
Withdrawal Multiplier
Required Nest Egg
Your Contributions
Investment Growth
Projected FIRE Year
Coast, Lean & Fat FIRE
Coast FIRE: $93,662.94
The amount invested today that would coast to your FIRE number by age 65, with no further contributions.
Lean FIRE
Fat FIRE
Portfolio vs. Your FIRE Number
Projected portfolio balance climbing toward your FIRE number — crossing it around age 49.
Related Calculators
How This Calculator Works
A FIRE calculator answers two questions at once: how big a portfolio makes work optional (your FIRE number) and how many years — at what age — you'll reach it. It uses the same future-value-with-contributions math as our Savings Goal Calculator and Retirement Savings Calculator, but instead of projecting a balance at a fixed age 65 (Retirement Savings) or a monthly amount for a dated target (Savings Goal), it solves for the moment your balance reaches your FIRE number — the early-independence question that defines FIRE.
Your FIRE Number (the 25× rule)
FIRE number = annualExpenses / (SWR / 100)
multiplier = 100 / SWR (25× at 4%)
Your FIRE number is your annual expenses divided by a safe withdrawal rate. Dividing by 4% is the same as multiplying by 25, so $40,000 of yearly spending needs a $1,000,000 portfolio. The "4% rule" and the "25× rule" are two ways of saying the same thing; lower the SWR (say 3.5%) and the multiplier — and the number — climbs.
Years & Age to FIRE (NPER)
t = ln((FIRE + C/r) / (P + C/r)) / ln(1 + r)
FIRE age = currentAge + ceil(t)
We grow your current portfolio (P) plus your annual contributions (C) at your real return (r) until the balance hits your FIRE number, then solve for the years t. At a 0% return it falls back to the linear t = (FIRE − P) / C. Your FIRE age is simply your current age plus those years.
Coast FIRE
Coast FIRE = FIRE / (1 + r)^n
n = targetRetireAge − currentAge
Coast FIRE is the amount you'd need invested today so that, with no further contributions, compounding alone carries it to your full FIRE number by your target retirement age. We discount your FIRE number back to the present at your expected return over those years. When your current portfolio passes it, you've "reached Coast FIRE" and can ease off saving.
Real Returns, Savings Rate & Lean/Fat
savingsRate = annualContribution / income x 100
Lean = 0.70 x expenses / swr · Fat = 2 x expenses / swr
By default the expected return is treated as a real (after-inflation) return, so the FIRE number and timeline both stay in today's dollars — no need to guess future inflation. Enter your income and the tool shows your savings rate, the biggest lever on time-to-FI, plus rough Lean and Fat FIRE figures for context.
Every figure comes from you and the math is deterministic — the same inputs always produce the same result. There are no live market returns, no maintained tax or inflation tables, and no Monte Carlo or historical backtest; the 4%/25× is a convention you can edit and the defaults are plain illustrative placeholders. For raw growth math see our Compound Interest Calculator, and to model an allocation's risk and return see the Investment Portfolio Calculator.
Tips for Reaching Financial Independence
Your Savings Rate Is the Biggest Lever
More than your exact rate of return, your savings rate decides how soon you reach FI. Raising it does double duty: it puts more money to work and implies you live on less, which directly lowers your FIRE number. Saving around half your income can compress the journey to roughly 15–17 years, while a 10% rate can stretch it past 40. Enter your income above to see your savings rate and watch the FIRE date move as you raise it.
Think in Real, Today's-Dollar Terms
This calculator uses a real (after-inflation) return by default, so your FIRE number and timeline stay in today's purchasing power — the most intuitive way to plan, since your expenses are also in today's dollars. A stock-heavy portfolio has historically returned roughly 7% after inflation, so 5%–7% is a sensible real-return assumption. If you'd rather think in nominal terms, flip on the advanced inflation toggle and the tool converts for you.
Treat the 4% Rule as a Guideline
The 4% rule (25× spending) comes from the Trinity Study and a 30-year horizon — a useful default, not a guarantee. Early retirees planning for 40–50 years often prefer a more conservative 3% to 3.5% withdrawal rate, which raises the FIRE number but adds a safety margin against a bad sequence of returns. Because the SWR is an input here, stress-test a lower rate and see how much larger your goal becomes before you commit to a number.
Use Coast FIRE to Buy Flexibility
You don't have to sprint all the way to full FIRE. Once your portfolio reaches your Coast FIRE number, compounding alone will carry it to your FIRE number by your target retirement age — even if you stop contributing. Hitting that milestone lets you downshift to a less stressful or lower-paying job and only cover your current expenses. Set your target retirement age above to see your Coast FIRE number and whether you've already passed it.
Common Ways People Use a FIRE Calculator
Find Your FIRE Number
FIRE NumberThe starting point for any FIRE plan is the number itself. Enter the annual spending you expect once you are financially independent and your safe withdrawal rate, and the calculator shows the nest egg that sustains it — your annual expenses divided by the SWR, which is 25× your spending at the classic 4% rate. Adjust the SWR to see how a more conservative rate raises the target.
See How Savings Rate Changes the Timeline
Savings RateWant to know what a raise or a frugality push really buys you? Enter your income to reveal your savings rate, then bump your annual contribution up or down and watch the years-to-FIRE and FIRE age move. It makes the single most powerful FIRE lever tangible — often shaving years or even decades off the journey.
Check Your Coast FIRE Point
Coast FIREMaybe you do not want to retire early — you just want the freedom to stop saving so hard. Set your target retirement age and the calculator shows your Coast FIRE number: the amount that, left untouched, compounds to your full FIRE number by that age. When your current portfolio passes it, you have reached Coast FIRE and can ease off contributions.
Compare Lean vs Fat FIRE Targets
Lean / FatFinancial independence is not one number — it scales with your lifestyle. The Lean (roughly 70% of expenses) and Fat (about 2× expenses) readouts show the range, from a frugal early finish line to a more generous one that takes longer to reach. Use them to frame how much your spending choices move both the FIRE number and the timeline.
What This Calculator Assumes
To keep results deterministic and evergreen, the FIRE math rests on a few clear assumptions:
- •Real returns, today's dollars: by default your expected return is treated as a real (after-inflation) return, so the FIRE number and timeline stay in today's purchasing power and you never have to forecast inflation. An optional advanced toggle lets you enter a nominal return plus an inflation rate, and the tool derives the real return for you.
- •A constant-return projection: the tool grows your portfolio at a single, steady return with constant annual contributions (no step-ups), using annual compounding. Real markets are volatile, so treat the years-to-FIRE as a smooth estimate rather than a promise — your actual path will zig and zag around it.
- •No taxes, sequence risk, or Monte Carlo: it deliberately leaves out income taxes, investment fees, Social Security, pensions, sequence-of-returns risk, and historical-backtest or Monte Carlo success probabilities. Those depend on changing law and assumptions that would make the tool less transparent. For withdrawal-sequence stress-testing, pair this with a dedicated backtesting tool.
- •The 4% rule is a guideline, not a guarantee: the 4%/25× convention comes from the Trinity Study and a 30-year horizon, and is fully editable here. Lean (≈70% of expenses) and Fat (≈2× expenses) figures are rough context, not prescriptions. Edge cases — already financially independent, zero contribution, 0% return, a 60+ year horizon — show friendly messages rather than NaN or infinity.
Disclaimer: This tool provides estimates for educational and personal planning purposes and is not financial, tax, or investment advice. The 4% rule and your expected return are assumptions, not guarantees — actual returns, inflation, taxes, and spending will vary, and a poor sequence of returns early in retirement can affect outcomes that simple rules don't capture. Consider your own circumstances and consult a qualified financial professional before making decisions.
Frequently Asked Questions
What is FIRE (Financial Independence, Retire Early)?
FIRE is a movement and a milestone: you accumulate enough invested assets that the returns can cover your living expenses indefinitely, making paid work optional. The "FI" (financial independence) is the core — having a portfolio large enough to live on — while "RE" (retire early) is the optional choice to stop working once you get there. People pursue it by saving and investing a high share of their income for years or decades until they hit their FIRE number. This calculator focuses on the two questions that define the journey: how big does your portfolio need to be, and how soon can you reach it.
What is the 4% rule and the safe withdrawal rate?
The 4% rule is a widely cited guideline, popularized by the Trinity Study, suggesting you can withdraw 4% of your portfolio in your first year of retirement and adjust that amount for inflation each year, with a high probability of the money lasting 30+ years. The "safe withdrawal rate" (SWR) is that withdrawal percentage — 4% is the classic default, though some FIRE planners use a more conservative 3% to 3.5% for very long retirements, or up to 5% if they're flexible. A lower SWR means a bigger nest egg is required; a higher SWR means a smaller one. This calculator lets you set the SWR yourself and shows the matching multiplier (4% equals 25×).
How is my FIRE number calculated?
Your FIRE number is simply your annual retirement expenses divided by your safe withdrawal rate. At a 4% rate, dividing by 0.04 is the same as multiplying by 25 — so if you spend $40,000 a year, your FIRE number is $1,000,000. Lower your spending or accept a higher withdrawal rate and the number drops; raise your spending or use a more conservative rate and it climbs. It represents the portfolio size at which your investments can sustainably cover your lifestyle.
How long will it take me to reach financial independence?
That depends on what you've already invested, how much you add each year, and your expected return. The calculator grows your current portfolio plus your annual contributions at your real return until the balance reaches your FIRE number, then reports the number of years and the age you'll be. For example, starting with $50,000, adding $24,000 a year at a 7% real return, you'd reach a $1,000,000 FIRE number in roughly 19 years. Increasing your contributions or trimming your expenses both shorten the timeline — often dramatically.
What is Coast FIRE?
Coast FIRE is the point at which your existing investments, left completely untouched, will grow to your full FIRE number by your target retirement age — without any further contributions. Once you've reached it, you only need to earn enough to cover your current expenses; compounding does the rest of the heavy lifting toward retirement. The Coast FIRE number is your FIRE number discounted back to today by your expected return over the years until that target age (FIRE number ÷ (1 + return)^years). It's a popular milestone because it buys flexibility — you can downshift to a less stressful or lower-paying job once you hit it.
What is the difference between Lean FIRE and Fat FIRE?
Lean FIRE means reaching financial independence on a lean, frugal budget — lower annual expenses, so a smaller FIRE number and an earlier finish line, but less spending room. Fat FIRE means funding a more generous lifestyle, which requires a larger portfolio and usually takes longer to reach. Regular FIRE sits in between. Because your FIRE number is just expenses divided by your withdrawal rate, your spending level scales the number directly — which is why this calculator shows rough Lean and Fat figures alongside your main number for context.
How does my savings rate affect when I can retire early?
Your savings rate — the share of your income you invest — is the single most powerful lever in FIRE, more so than your exact rate of return. A higher savings rate does double duty: it puts more money to work and implies you live on less, which lowers your FIRE number. Famously, saving around 50% of your income can put financial independence within roughly 15–17 years, while a 10% rate can take 40+ years. If you enter your income, this calculator shows your savings rate so you can see how raising it pulls your FIRE date closer.
Is the 4% rule still safe?
The 4% rule has held up well historically, but it isn't a guarantee — it was based on a 30-year horizon and specific stock/bond mixes, and early retirees planning for 40–50 years sometimes prefer a more conservative 3% to 3.5% withdrawal rate for extra safety. The biggest risk is a poor sequence of returns early in retirement (a market crash just after you stop working), which simple rules don't fully capture. Many FIRE practitioners stay flexible — trimming spending in down years — which improves the odds considerably. Because this calculator lets you set your own withdrawal rate, you can stress-test a more conservative number and see how much larger your FIRE goal becomes.
Should I use a real or nominal rate of return?
This calculator uses a real (inflation-adjusted) return by default, which keeps your FIRE number and timeline in today's dollars — the most intuitive way to plan, since your expenses are also in today's dollars. A diversified stock-heavy portfolio has historically returned roughly 7% after inflation, so 5%–7% is a reasonable real-return assumption. If you'd rather work in nominal terms, the advanced inflation toggle lets you enter a nominal return (e.g., 10%) and an inflation rate (e.g., 3%), and the tool converts to a real return for you. Either way, results stay in today's purchasing power so the FIRE number stays meaningful.
How is this different from a retirement or savings-goal calculator?
A retirement calculator typically projects what you'll have at a fixed age like 65 and whether it covers a desired income; a savings-goal calculator tells you the monthly amount to hit a dated target. A FIRE calculator flips the question: it defines the number that makes work optional (your expenses ÷ a safe withdrawal rate) and solves for how soon you can get there — often well before 65 — through the savings-rate and 4%-rule lens. The underlying compound-growth math is shared, but the framing, the Coast/Lean/Fat readouts, and the early-independence focus are specific to FIRE. For a traditional age-65 projection see our Retirement Savings Calculator, and for a dated savings target see our Savings Goal Calculator.
What expenses and savings should I include?
For annual expenses, use the yearly spending you expect to need once you're financially independent, in today's dollars — your realistic lifestyle cost, not your current gross income. For current investments, include everything you've earmarked for FI as a single pool: brokerage accounts, 401(k)s, IRAs, and other invested assets (cash earmarked as an emergency fund is usually kept separate). For your annual contribution, add up everything you invest in a year, including any employer match. The cleaner your inputs, the more meaningful your FIRE number and timeline.
Does this calculator account for taxes, fees, or Social Security?
No — by design it's a clean, deterministic projection, so it leaves out income taxes, investment fees, Social Security, pensions, and market-sequence (Monte Carlo or historical backtest) modeling. Those depend on changing law and assumptions that would make the tool less transparent and require constant updates. What you get is the evergreen core: your FIRE number, the years and age to reach it, your Coast FIRE point, and a projection — all on the numbers you enter. For sequence-of-returns stress-testing, pair this with a dedicated backtesting tool, and consult a financial professional for personalized advice.