What Is the FI Number?
Your Financial Independence number is the amount of invested money needed to cover your annual expenses through withdrawals alone, indefinitely, with no further work required. It's most commonly calculated as your annual expenses divided by your chosen withdrawal rate — at a 4% withdrawal rate, that's the same thing as the widely used 25x rule (25 × annual expenses).
FI vs. Coast FIRE vs. Barista FIRE
Financial IndependenceFull number — 100% of expenses from withdrawals, no work at all
Coast FIREStop contributing, but keep working full-time until traditional retirement age
Barista FIREPart-time income covers the gap, portfolio only needs to cover the rest
This calculator finds the biggest number of the three — the one that requires no ongoing income of any kind. If that timeline looks too long, the Coast FIRE and Barista FIRE calculators show two different ways to get to a lower-stress life sooner, using a smaller number.
Worked Example
With $60,000 in annual expenses and a 4% withdrawal rate, the FI number is $60,000 ÷ 0.04 = $1,500,000. Starting from $300,000 already invested, contributing $2,000/month at a 7% expected return, that number is reached in about 16 years.
What This Doesn't Account For
- Taxes — this is a gross withdrawal estimate; actual after-tax income depends on account type
- Sequence of returns risk — a downturn in your first few withdrawal years affects your portfolio more than the same downturn later
- Changing expenses — healthcare, housing, and lifestyle costs can shift meaningfully over a multi-decade retirement
Frequently Asked Questions
What is the FI number?
Your FI (Financial Independence) number is the portfolio size needed to cover your annual expenses through withdrawals alone, indefinitely, with no further work required. It's commonly calculated as your annual expenses divided by your withdrawal rate — equivalent to the 25x rule at a 4% withdrawal rate.
How is this different from Coast FIRE or Barista FIRE?
This is the full, traditional FI number — enough to cover 100% of expenses through withdrawals with no work at all. Coast FIRE assumes you keep working full-time while your portfolio grows untouched to a future target. Barista FIRE assumes part-time income covers part of the gap, so the portfolio only needs to cover the rest.
Is the 4% withdrawal rate still considered safe?
4% remains the most commonly cited starting point, based on historical research into how long a diversified portfolio can sustain withdrawals over roughly 30 years. Some planners use 3-3.5% for extra safety margin, especially for a longer retirement horizon or more conservative planning.
Does this number account for taxes?
No — this is a gross withdrawal estimate. Your actual after-tax income will depend on which accounts the money comes from (taxable brokerage, traditional 401k/IRA, or Roth) and your tax situation at the time.