Beacon Blog

FI calculator: calculate your financial independence date

Use this FI calculator to estimate when your investable assets may reach the number needed to support your target spending.

FI Calculator July 30, 2026 8 min read

An FI calculator estimates two things: your financial independence number and the date your current assets may reach that number. Beacon calculates a deterministic FI date from your investable assets, annual spending target, annual savings, expected return, and withdrawal rate.

Enter your details.
Receive your date.

Adjust assumptions to calculate a financial independence date. This model uses one deterministic path, not a probability range.

Not financial advice. Assumes constant nominal returns.

Your number $2,400,000
Your date JAN 2039
Time to FI 12y 8m
Progress to number 20.1%
$482k today $2.40M target
Projection Deterministic · one outcome
Get your date

How the FI calculator works

The calculator starts with your annual spending target and withdrawal rate. Dividing spending by withdrawal rate gives your financial independence number. It then projects your current investable assets forward with annual savings and expected returns until the portfolio reaches the target.

Annual spending ÷ Withdrawal rate = FI number

Inputs you need

  • Current assets: Use investable assets that can plausibly fund future spending.
  • Annual spending: Use the lifestyle cost you want the portfolio to support.
  • Annual savings: Use the amount you expect to add to investable assets each year.
  • Expected return: Use a long-term assumption you can explain and revisit.
  • Withdrawal rate: Use the percentage of the portfolio you expect to withdraw annually.

Example: when can I retire?

If you want to spend $96,000 per year and use a 4% withdrawal rate, your FI number is $2,400,000. If you currently have $482,300 invested, save $38,400 per year, and assume a 6.8% annual return, the calculator estimates when those inputs reach the target.

That date is not a promise. It is the output of the assumptions you selected. Change spending, savings, returns, or withdrawal rate and the date should change with them.

What the calculator does not do

This is a deterministic financial independence calculator. It does not run Monte Carlo simulations, optimize taxes, model account withdrawal order, estimate future inflation, or provide retirement advice. Its job is narrower: make the relationship between your assumptions and FI date visible.

Beacon approach: A useful FI calculator should be transparent enough to challenge. Your date should feel traceable, not mysterious.

Related guides

For the core target calculation, start with what is your financial independence number?. For the asset input, read investable assets vs. net worth. For the rate assumption, read how to choose a withdrawal rate.

FI calculator FAQ

What is an FI calculator?

An FI calculator estimates the portfolio target and date when invested assets may be able to support a chosen annual spending level, based on user-selected assumptions.

How do you calculate an FI date?

First calculate the FI number by dividing annual spending by withdrawal rate. Then project current assets forward using expected savings and return assumptions until assets reach that target.

Is this retirement advice?

No. Beacon's calculator is educational and deterministic. It does not provide financial, investment, tax, legal, or retirement planning advice.

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