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FIRE Calculator

Find your FIRE number and the age you could reach financial independence, based on what you've invested, what you earn and what you spend. Compare Lean FIRE, traditional FIRE, Fat FIRE and Coast FIRE side by side and see the portfolio year by year.

Updated November 4, 2026. Free, no sign-up; everything runs in your browser and nothing you type is stored.

FIRE calculator

Your ageInvested now ($)Take-home income a year ($)Spending a year ($)

Real return after inflation (%)Withdrawal rate (%)Lean FIRE spending ($)Fat FIRE spending ($)Coast FIRE: normal retirement age

Your FIRE number

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–Time to financial independence

–Savings rate

–Coast FIRE number today

How the FIRE calculator works

FIRE number = annual spending ÷ withdrawal rate. At a 4% withdrawal rate that's 25 × spending: $50,000 a year needs $1,250,000. The calculator grows your portfolio by the real (after-inflation) return each year, adds what you save (take-home income − spending), and counts the years until it reaches the target.

The 4% figure comes from studies of historical US stock and bond returns (the 1998 Trinity study and earlier work by William Bengen), which found a 4% first-year withdrawal, raised with inflation, lasted 30 years in almost every past period. Early retirees planning for 40 to 50 years often use 3.25% to 3.5% for extra safety.

Savings rate retirement calculator: why the savings rate matters most

Saving more works twice: the portfolio grows faster and the target shrinks because you've learned to live on less. Starting from zero at a 5% real return and 4% withdrawals: a 10% savings rate takes about 52 years, 25% about 32, 50% about 17, and 70% about 9.

Lean, Fat and Coast FIRE

Lean FIRE: a frugal budget, often under about $40,000 a year.
Fat FIRE: a comfortable or luxury budget, often $100,000 or more.
Coast FIRE: enough invested that it would grow to your FIRE number by normal retirement age with no more saving. See the Coast FIRE calculator for details.

Before age 59½, plan how you'll reach retirement accounts (Roth contribution withdrawals, a Roth conversion ladder, or substantially equal periodic payments), and budget for health insurance until Medicare at 65.

Common questions

How do I calculate my FIRE number?

Divide your yearly spending by your withdrawal rate. At 4%, multiply spending by 25: $50,000 a year needs $1.25 million.

How long until I can retire early?

It depends mostly on your savings rate. Saving 50% of take-home pay from zero takes about 17 years at a 5% real return.

Is the 4% rule safe for early retirement?

It held for 30-year retirements in US history. For 40+ years many people use 3.25% to 3.5%.

What is the difference between Lean FIRE and Fat FIRE?

Lean FIRE targets a frugal budget (often under $40,000 a year); Fat FIRE a larger one ($100,000+).

Should I use real or nominal returns?

Real (after inflation), so the FIRE number stays in today's dollars. 5% real is roughly 7% to 8% nominal minus 2.5% to 3% inflation.

Sources

General information, not financial, tax or legal advice. Check important numbers with the official source before acting on them.