FIRE Calculator — Financial Independence, Retire Early
Calculate your FIRE number — the amount you need to achieve financial independence and retire early. Based on the 4% safe withdrawal rate rule.
A FIRE calculator estimates how long until you can quit your day job and live off your investments — the core question behind the Financial Independence, Retire Early movement. "FIRE" stands for Financial Independence, Retire Early, and its math rests on one elegant idea: once your invested assets reach roughly 25× your annual expenses, a sustainable 4% withdrawal rate can cover your lifestyle indefinitely. Our free FIRE calculator takes your current net worth, income, expenses, and expected investment return, and returns a target FIRE number plus the year you'll hit it.
This matters because early retirement planning is radically more sensitive to your savings rate than to your income. A household saving 10% of take-home pay needs roughly 51 working years to retire; at 25% it's about 32 years; at 50% it drops to around 17 years; at 65% it's about 10 years. Your expenses define both how fast you accumulate (higher savings rate) and how small a nest egg you need (lower target multiple). That compounding of both sides is why the FIRE community obsesses over the savings rate metric above almost everything else.
Who should use this FIRE calculator? Aggressive savers targeting early retirement, mid-career professionals sanity-checking whether a coast-FIRE glide path is realistic, and anyone curious about the "F-you money" threshold. Variants like coast FIRE, lean FIRE, and barista FIRE adjust the target multiple for different lifestyles; the savings rate calculator helps you measure the input that matters most. This free tool is for educational modeling only and is not financial advice — for decisions like leaving a career, speak with a certified financial planner.
Quick answer: Your FIRE number equals annual expenses divided by your safe withdrawal rate — roughly 25x expenses at the classic 4% rule. A household spending $40,000/year needs $1,000,000 invested (or about $1.14M at a more conservative 3.5% SWR). This calculator projects your exact FIRE number and years to get there based on your savings rate and expected returns.
Inputs
Quick presetsYour target yearly spending in retirement — in today's dollars. Pull 3 months of bank statements and annualize; most people underestimate by 20–30%.
Total investable assets today (401k, IRA, brokerage, HSA, taxable). Exclude your primary residence.
How much you add to investments every month, including employer 401(k) match.
3.5% recommended for 40+ year retirements (Trinity Study update). 4% is the classic 30-year rule; below 3% is ultra-conservative.
Expected REAL return after inflation. 7% is the long-run historical US equity average; use 5% for a more conservative 60/40 mix. Don't mix nominal returns with today's-dollar expenses.
Results
How to use this calculator
Six key inputs drive the calculation. **Current age** anchors the timeline. **Current invested assets** is liquid net worth — 401(k), IRA, brokerage, HSA — excluding your primary residence. **Annual after-tax income** should reflect actual take-home pay.
**Annual expenses** is the single most important input: include rent/mortgage, food, transport, insurance, travel, subscriptions. Many people underestimate this by 20–30% — pull three months of bank statements and annualize. **Expected real return** (after inflation) is typically 4–5% for a diversified stock portfolio based on historical data. **Safe withdrawal rate** defaults to 4% based on the Trinity Study, but lean-FIRE followers targeting 40+ year horizons may prefer 3.5%.
Output: a FIRE number (expenses ÷ withdrawal rate), years to FIRE given your current savings trajectory, and the projected age at which you cross the line.
Worked examples
Chloe, 32, standard FIRE path
Chloe is a 32-year-old product manager earning $140,000 after tax with $180,000 invested. She spends $48,000 per year and saves the rest — a 66% savings rate. Her FIRE number = $48,000 × 25 = $1.2M. At a 5% real return and $92,000 annual contributions, she hits FIRE in approximately 9 years, at age 41. If lifestyle creep raises her expenses to $60,000 (dropping her savings rate to 57%), the target jumps to $1.5M and her timeline stretches to roughly 12 years.
Derek, 40, coast FIRE
Derek is 40, has $420,000 invested, and spends $55,000/year. Full FIRE would require $1.375M. At 5% real return, $420,000 grows to about $1.11M over 20 years even with zero further contributions — short of the target but close. To hit coast-FIRE status, he needs about $520,000 before he can stop contributing. An additional $2,500/month for three more years gets him there, after which he can shift to lower-stress work.
The $500/month difference — Chloe vs Derek
Sensitivity matters more than the base rate. Take two 35-year-olds with identical $150,000 portfolios and $50,000 annual expenses (FIRE number: $1.43M at 3.5% SWR, 5% real return). Chloe saves $2,000/month and reaches FIRE in about 21 years, at age 56. Derek saves $2,500/month — only $500 more — and hits it in roughly 18.5 years, at age 53.5. That marginal $500/month (often one takeout-food or subscription-audit away) buys back 2.5 years of life. Push it to $3,000/month and the timeline drops to ~16.5 years — a 4.5-year gain versus the baseline. This is why the FIRE community obsesses over the savings rate: each extra dollar saved both shrinks the gap and grows faster via compounding. Before obsessing over optimal asset allocation or chasing a higher return, audit your monthly savings — it's the lever with the highest torque.
Frequently asked questions
What is the 4% rule?
The 4% rule comes from the 1998 Trinity Study, which analyzed US market data from 1926–1995. A retiree holding a 50/50 or 60/40 stock/bond portfolio who withdrew 4% in year one and adjusted for inflation thereafter had roughly a 95% success rate over rolling 30-year periods. For FIRE horizons of 40+ years, many experts suggest using 3–3.5% instead.
Why 25× annual expenses?
It's arithmetic: 1 ÷ 0.04 = 25. If you pick a 3.5% withdrawal rate, the multiple becomes 28.6×. At 3% it's 33×. The multiple scales directly with your chosen safe withdrawal rate, not with your income.
What's the difference between lean / fat / coast / barista FIRE?
Lean FIRE: below $40k/year, sub-$1M nest egg. Fat FIRE: $100k+/year, $2.5M+ portfolio. Coast FIRE: current assets will compound to full FIRE by traditional retirement age without further contributions. Barista FIRE: coast plus part-time work for healthcare and basic expenses.
Does this account for inflation?
This calculator uses real (inflation-adjusted) returns, meaning both your return and your expenses are expressed in today's dollars. Don't mix nominal returns with today's-dollar expenses — that's a common error that overstates projections.
What if I'll earn income in early retirement?
This model assumes zero future earned income — the most conservative framing. In practice, most FIRE adherents earn something (side projects, consulting, part-time). Treating it as zero acts as a sequence-of-returns buffer.
What about sequence-of-returns risk?
A severe bear market in the first 5–10 years of retirement can permanently impair a portfolio even if 30-year average returns are fine. Common mitigations: hold 1–3 years of expenses in cash, use a flexible withdrawal rule instead of strict 4%, or adopt a conservative equity glide path.
How does US healthcare factor in before Medicare?
It's the biggest hole in most FIRE plans. ACA marketplace plans typically run $500–$1,500/month; subsidies are possible based on reported income. Many experts suggest budgeting $15–20k/year for a couple's healthcare pre-65, and not assuming current subsidies persist.
Can you FIRE with kids or a mortgage?
Harder, but doable. USDA estimates suggest $15–20k/year per child through age 17. A mortgage raises current expenses but a paid-off home lowers them later — many households target 'FIRE at mortgage payoff' as a natural milestone.