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FIRE Number Calculator

Calculate the portfolio size you need to retire early and how long it will take.

Updated June 2026 · Editorial standards

Your details

$
$
$
%
%
FIRE number
$1,500,000
Years to FIRE
20.5 yrs
Monthly savings needed
$1,983
Portfolio at FIRE
$1,509,248

You need $1,500,000 to retire on $60,000/year at a 4% withdrawal rate. At your current saving pace you'll reach FIRE in 20.5 yrs.Saving $1,983/month instead of $2,000/month would close the gap in the same 20.5 yrs.

Portfolio growth to FIRE target

FIRE readiness

Just startingNearly there
Just starting7% of FIRE number

$100,000 saved of $1,500,000 target. $1,400,000 to go.

By the KalkWise Editorial Team Reviewed for accuracy Updated June 2026

What is the fire number calculator?

In short

Your FIRE number is your annual expenses divided by your safe withdrawal rate (typically 4%). To retire on $60,000/year at a 4% withdrawal rate you need $1,500,000. Use the compound growth formula to determine how many years it takes to reach that target from your current savings and monthly contributions.

This FIRE number calculator tells you exactly how large a portfolio you need to retire early, how many years you are from reaching it at your current saving rate, and how much you'd need to save per month to hit FIRE sooner.

How to use this calculator

  1. 1Enter your expected annual expenses in retirement (today's dollars).
  2. 2Enter your current total portfolio — 401(k), IRA, brokerage, and savings.
  3. 3Enter how much you contribute per month.
  4. 4Set your expected annual return and preferred withdrawal rate.
  5. 5Read your FIRE number, years to FIRE, and monthly savings needed.

The formula

FIRE=expensesrate
FVn=S(1+r)n+C×(1+r)n−1r
FIRE number = annual expenses ÷ withdrawal rate. Years to FIRE is solved by growing the portfolio at the expected return until it reaches the target.
FIRE
— Required portfolio size for financial independence
expenses
— Annual spending in retirement
rate
— Safe withdrawal rate (e.g. 0.04 for 4%)
S
— Current savings / portfolio balance
C
— Monthly contribution
r
— Monthly investment return (annual ÷ 12)
n
— Number of months

Worked example

The scenario

$60,000/year expenses, $100,000 saved, $2,000/month contribution, 7% return, 4% withdrawal rate.

gives

The result

FIRE number = $60,000 ÷ 0.04 = $1,500,000. With $2,000/month at 7% from $100,000, you'd reach $1.5M in approximately 21 years.

Common use cases

  • Setting a long-term FIRE savings target
  • Testing how changing your withdrawal rate affects the number
  • Seeing how much more to save monthly to retire years earlier
  • Comparing lean FIRE (lower expenses) vs fat FIRE (higher expenses)

Limitations & assumptions

  • Assumes a constant real return — market sequence-of-returns risk is not modelled.
  • Does not account for taxes on withdrawals from traditional retirement accounts.
  • Inflation is not separately modelled — use a real (after-inflation) return for accuracy.
  • The 4% rule is a guideline based on historical US data; early retirees often use 3–3.5% for longer horizons.

Frequently asked questions

The 4% rule (from the 1994 Trinity Study) states that withdrawing 4% of your portfolio annually, adjusted for inflation, has historically sustained a portfolio for at least 30 years. For early retirees planning a 40–50 year retirement, many financial planners recommend 3–3.5%.

Disclaimer: KalkWise calculators are provided for general informational and educational purposes only and do not constitute financial, investment, tax, or legal advice. Results are estimates based on the figures you enter and the assumptions described above. Actual outcomes will vary. Consult a qualified professional before making financial decisions.