FIRE Calculator
Find your financial-independence number and timeline.
Details
Your FIRE number
$1,000,000
25× your annual expenses
Time to reach it
20 yr 7 mo
Total invested
$420,500
This works out your FIRE number, the portfolio needed to live off investments, and how long it takes to reach at your savings rate.
It shows the target and the timeline together, since the savings rate drives the timeline far more than income does.
FIRE and the 25x rule
FIRE stands for Financial Independence, Retire Early. The idea is to build a portfolio large enough that its withdrawals cover your living costs, at which point working becomes optional.
The target is usually set with the 25x rule: save 25 times your annual expenses. That comes straight from the 4% withdrawal rate, since 1 ÷ 0.04 is 25. Someone spending $50,000 a year needs $1,250,000.
The insight that makes FIRE different from ordinary retirement planning is that your savings rate decides the timeline, not your income. Saving 50% of your income means you live on half of it, which both fills the portfolio faster and lowers the target it has to reach. Both effects pull in the same direction.
These are approximate, assuming a 7% real return and starting from zero. The reason higher rates compress the timeline so sharply is that saving more also means needing less.
What to enter
- Annual expenses
- Your target spending in retirement, not your current income. This sets the whole target, so it deserves the most care.
- Current savings
- What you already have invested. It compounds for the entire period.
- Annual savings
- How much you add each year. As a share of income this is the savings rate, which is the number that matters.
- Expected return
- 7% is common for a diversified stock portfolio. Some people use a real return of about 4-5%, having already netted off inflation.
- Withdrawal rate
- 4% gives the 25x target. A more cautious 3.5% gives 28.6x, and 3% gives 33x.
The variants people mean by FIRE
- Lean FIRE
- A deliberately small target, often under $1 million, supporting a frugal lifestyle. Faster to reach and less tolerant of surprises.
- Regular FIRE
- 25x your actual current expenses. The standard version.
- Fat FIRE
- A larger target supporting a comfortable or high-spending lifestyle. Usually needs high income as well as a high savings rate.
- Coast FIRE
- Enough invested that, without adding another dollar, it grows to your target by normal retirement age. You still work, but only for current costs.
- Barista FIRE
- Partly there, covering the rest with part-time work, often chosen for health insurance rather than income.
What this assumes
The 4% rule comes from a study of 30-year retirements. Early retirement can mean 40 or 50 years, which the original research did not test.
Health insurance before Medicare eligibility is a large, real cost that FIRE plans routinely underestimate.
How to calculate your FIRE number
Set the target from your expenses, then work out how long your savings rate takes to reach it.
- annual expenses
- What you will actually spend, including health insurance and tax
- withdrawal rate
- 0.04 for the standard rule; lower for a longer retirement
Work out your real annual expenses. Track actual spending rather than estimating. Add health insurance, which an employer may currently be hiding from you, and tax on withdrawals.
Multiply by 25. That is the 4% version. Use 28.6x for 3.5% or 33x for 3% if you want a longer safety margin.
Work out your savings rate. Annual savings divided by take-home income. This is the number that determines your timeline.
Project the years to target. Compound existing savings plus annual contributions until they reach the number. Then stress-test it against a worse return.
See a worked example: a 50% savings rate from zero
- Expenses
- $50,000 a year
- Income
- $100,000, saving $50,000
- Return
- 7% a year
FIRE number: $50,000 × 25 = $1,250,000.
Saving $50,000 a year at 7% from zero reaches that in about 15 years.
Now change one thing. Cutting expenses to $40,000 lowers the target to $1,000,000 and raises annual savings to $60,000, reaching it in about 11.4 years.
A $10,000 spending cut moved the finish line forward by about three and a half years, which is why FIRE discussions focus on spending rather than income.
$1,250,000, reached in about 15 years
Frequently asked questions
A guideline that you can withdraw 4% of your portfolio in the first year of retirement, adjust that amount for inflation each year after, and be unlikely to run out over 30 years.
It comes from the Trinity Study and related research on historical US market returns. It is a useful starting point, not a guarantee, and its 30-year horizon is exactly the assumption early retirement breaks.
Less safe than for 30, which is the honest answer. The original research tested 30-year periods, and a portfolio has to survive considerably longer if you retire at 40.
Many in the FIRE community use 3.25% to 3.5% instead, giving a target of about 29-31 times expenses. Others keep 4% and plan to stay flexible, cutting spending in bad years rather than mechanically withdrawing.
Having enough invested that it will grow to your full target by normal retirement age without any further contributions. You keep working, but only to cover current living costs.
It is a genuinely useful milestone because it arrives much earlier than full FIRE and immediately removes the pressure to save, which changes what work you are willing to do.
Health insurance is the big one. Retiring before Medicare eligibility means buying cover yourself, and for a family it can run well over $1,000 a month.
Tax is the other. Withdrawals from a traditional 401(k) or IRA are taxable income, so a $50,000 spending target needs more than $50,000 of withdrawals.
Yes, and the reason is that it works on both sides at once. Saving a higher share means the portfolio fills faster *and* the target is smaller, because the target is a multiple of what you spend.
Someone earning $200,000 and spending $180,000 needs $4.5 million and saves $20,000 a year. Someone earning $80,000 and spending $40,000 needs $1 million and saves $40,000. The second reaches independence far sooner.
The risk that a market fall early in retirement does lasting damage, because you are selling assets while they are down and they never fully recover.
Common defences are holding a cash buffer of one to three years, keeping spending flexible in bad years, or being willing to earn something part time early on. The order of returns matters more than the average, which is not intuitive.
Problems people actually run into
Building the target from income rather than spending
The FIRE number is 25 times what you spend, not 25 times what you earn. Using income inflates the target enormously and makes independence look unreachable.
Track actual spending for a few months before setting a number. Most people are surprised by the figure in both directions.
Treating 4% as a settled fact
The 4% rule was derived from 30-year retirements using historical US returns. Retiring at 40 means planning for 45 or more years, which is well outside what the research covered.
Run the number at 3.5% as well and see whether the plan still works. If a half-point change in the withdrawal rate breaks it, the plan has no margin.
Results are estimates for general information only and are not professional financial, medical, or legal advice. Read our full disclaimer.
Last updated: September 4, 2026