FIRE Calculator

Find your FIRE number, how many years until financial independence, and the age you could retire early — based on your savings rate and returns.

How the fire calculator works

FIRE — Financial Independence, Retire Early — is built on one number: the portfolio large enough that its safe withdrawals cover your spending forever. That FIRE number is your annual expenses divided by your safe withdrawal rate. At the classic 4% rate, that’s 25× your yearly expenses; a more cautious 3.5% rate pushes it to about 29×.

From there the calculator projects your net worth forward year by year. Each year your existing balance earns the expected return, and your annual savings (income minus expenses) are added on top. The year your net worth crosses the FIRE number is your financial-independence point, and the chart marks it against the target line.

Two inputs dominate the result: your savings rate and your expenses. A higher savings rate doesn’t just add money to invest — because expenses also set the FIRE number, spending less shrinks the target at the same time. That double effect is why someone saving 50% of income reaches FI in a fraction of the time of someone saving 10%.

How to use this calculator

Enter your current age and everything you’ve already saved and invested.
Enter your after-tax annual income and your annual expenses.
Set an expected annual return (a real, after-inflation rate keeps it conservative).
Set your safe withdrawal rate — 4% is the common default.
Press Calculate to see your FIRE number, years to FI, FI age, and net-worth chart.

Key terms

FIRE number: The portfolio that funds your expenses indefinitely: annual expenses ÷ withdrawal rate. At 4%, it equals 25× your yearly spending.
Safe withdrawal rate (SWR): The percentage of your portfolio you can withdraw each year with low risk of running out. The 4% rule comes from the Trinity study on 30-year retirements.
Savings rate: The share of your income you save and invest. It’s the strongest predictor of how soon you reach financial independence.

Tips

Focus on your savings rate above all — it cuts the time to FI from both directions by adding investments and lowering the target.
Use a real (after-inflation) return like 5–7% so your FIRE number stays in today’s dollars.
Consider a slightly lower withdrawal rate (3.25–3.5%) if you plan a very long, early retirement — it raises the target but lowers the risk of depletion.

Frequently asked questions

What is the 4% rule?

The 4% rule says you can withdraw 4% of your portfolio in the first year of retirement, adjust that dollar amount for inflation each year after, and have a high chance of the money lasting 30 years. It’s the basis for the 25× FIRE number, though early retirees often use a lower rate for longer horizons.

How is my FIRE number calculated?

Divide your annual expenses by your withdrawal rate (as a decimal). At a 4% rate, $40,000 of expenses needs $40,000 ÷ 0.04 = $1,000,000. Lowering your expenses or your withdrawal rate changes the target directly.

What’s the difference between FIRE, Lean FIRE, and Fat FIRE?

They differ by spending level. Lean FIRE targets a frugal lifestyle (lower expenses, smaller number), Fat FIRE targets a comfortable or luxurious one (higher expenses, larger number), and regular FIRE sits in between. All use the same math — only the annual-expenses input changes.

Should I use a real or nominal return?

For FIRE planning, a real (after-inflation) return is cleaner because it keeps your FIRE number in today’s dollars. If you use a nominal return instead, remember the resulting number is in future dollars and will buy less than it seems.

Does this account for taxes and healthcare?

Only indirectly — through the expenses you enter. To be realistic, your annual-expenses figure should include the taxes you’ll owe on withdrawals and the cost of health insurance, which is a major line item for early retirees who lose employer coverage.

What is Coast FIRE?

Coast FIRE is the point where your existing investments will grow to your FIRE number by traditional retirement age without any further contributions — so you only need to cover current expenses. You can approximate it here by setting savings to zero and seeing whether growth alone reaches the target.

Why does a higher savings rate matter so much?

Because it works on both sides of the equation. Saving more increases the money compounding toward your goal, while the lower spending it implies also reduces the FIRE number you’re aiming at. That’s why savings rate, not income, is the dominant driver of time to FI.

Planning further? Try the retirement calculator (401k & roth ira) or the compound interest calculator.

Retirement Calculator (401k & Roth IRA)

Project your retirement balance with employer match and compound growth, and compare Traditional vs. Roth after-tax outcomes.

Compound Interest Calculator

See how your savings grow over time with compound interest and regular monthly contributions.