FIRE Calculator

Estimate a FIRE portfolio target and how long a constant-return savings model takes to reach it.

To support $45,000 of annual spending with a 4% withdrawal-rate assumption, you need a FIRE number of about $1,125,000. With $50,000 already invested and saving $35,000 a year at 7%, you would reach it in about 15.8 years — around age 46 if you start at 30. This calculator estimates your financial-independence target and how long your current savings plan takes to reach it. Adjust spending, savings, return or withdrawal rate to model your own path.

Your plan

Calculations run in your browser. Inputs are not stored.

$
$

How much you save and invest each year.

$

Enter a nominal annual spending amount. Inflation is not applied automatically.

%

Illustrative assumptions only. Historical returns do not guarantee future results; test a range instead of treating 7% as a forecast.

%

Leave blank to hide the estimated FI age.

FIRE number — modeled portfolio target
$1,125,000

15.8 years to FI

Time to financial independence15.8 years
Estimated FI age46
Monthly spending target$3,750

FIRE target = annual spending ÷ withdrawal-rate assumption. Time to FI uses a constant-return accumulation model and does not model inflation, taxes, fees or return sequence.

PortfolioFIRE target

Show yearly breakdown
YearContributionsPortfolioFIRE target

The default 7% is an illustrative nominal annual return before inflation, not a forecast or a historical real return. If inflation adjustment is enabled, it is applied once to the nominal result. Do not subtract inflation again from an already real return.

How this calculation works

The FIRE number

Your FIRE number is a planning target derived from annual retirement spending and a withdrawal-rate assumption:

FIRE number = annual retirement spending ÷ withdrawal-rate assumption

At a 4% withdrawal rate, that's 25× your annual spending. For $45,000 a year, you need $1,125,000.

How we estimate years to FI

We simulate month by month: your current portfolio grows at the annual return (compounded monthly) and receives your annual contribution spread over 12 months. We count months until the balance reaches your FIRE number.

Assumptions

  • Contributions are invested at the end of each month; returns compound monthly at a constant annual rate.
  • Spending in retirement stays constant in nominal terms (not inflation-adjusted here).
  • Results are pre-tax and ignore fees, commissions and changes in spending.
  • No market volatility is modeled.
  • Results are hypothetical and for education only — not financial advice.

View the formula →

Educational purposes only. Not financial advice. See the full methodology and disclaimer.

Worked examples

See how different savings rates and withdrawal assumptions change your path to financial independence.

Example 1: The standard FIRE path

Current assets: $50,000 · Annual contribution: $35,000 · Retirement spending: $45,000/year · Return: 7% · Withdrawal rate: 4%

FIRE number
$1,125,000
Years to FI
15.8 years
Monthly spending
$3,750

At a 4% withdrawal-rate assumption, the target is 25× annual spending — $1,125,000 for a $45,000/year spending input. Starting with $50,000 and contributing $35,000/year at a 7% assumed return, the calculator reaches that target in about 15.8 years. If you're 30 now, the modeled FI age rounds to about 46. This is a deterministic planning scenario, not a forecast of market returns or retirement durability.

Example 2: High savings rate = much faster FI

Current assets: $50,000 · Annual contribution: $50,000 · Retirement spending: $40,000/year · Return: 7% · Withdrawal rate: 4%

Standard path
$1.125M · 15.8 years
High savings
$1.0M · 11.8 years

By increasing contributions from $35,000 to $50,000/year and reducing target spending from $45,000 to $40,000, your FIRE number drops to $1,000,000 and the model reaches it in about 11.8 years — roughly 4 years faster than the standard modeled path. This example shows how higher contributions and a lower spending target can shorten time to FI under the same return assumption. Cutting spending affects both sides of this formula: it can increase what you save now and reduce the portfolio target later.

Example 3: How your withdrawal rate changes everything

Same $45,000/year spending · same $50,000 start + $35,000/year contributions · 7% return

3% (lower)
$1.5M
18.8 years
4% (benchmark)
$1.125M
15.8 years
5% (higher)
$900k
13.6 years

Your withdrawal rate determines your FIRE number: at 3% you need 33.3× spending ($1.5M), at 4% you need 25× ($1.125M), at 5% you need 20× ($900k). The difference between 3% and 5% is $600,000 and about 5.3 modeled years with these inputs. A higher withdrawal-rate assumption lowers the target but can raise depletion risk in real retirement markets. The 4% rule comes from historical U.S. withdrawal research commonly centered on 30-year horizons; for longer horizons, test lower rates such as 3–3.5% as stress scenarios rather than treating any one rate as a recommendation.

All examples are hypothetical and assume a constant 7% annual return with no taxes, fees, or inflation. Actual investment results will vary. FIRE carries risks including market downturns, unexpected expenses, and changes in tax law. See full disclaimer.

FIRE, explained

What does FIRE mean?
FIRE stands for Financial Independence, Retire Early. It's the point where your investments can support your living expenses without needing a job — so you can retire or choose how you spend your time.
What is a FIRE number?
Your FIRE number is the portfolio size needed to fund retirement: annual retirement spending divided by your chosen withdrawal-rate assumption. At a 4% rate, you need 25× your annual spending ($45,000 ÷ 0.04 = $1,125,000).
What withdrawal rate should I test?
4% is a historical planning benchmark commonly tested on U.S. stock/bond portfolios over 30-year periods. Lower rates such as 3% are useful stress-test scenarios; higher rates reduce the target but can increase depletion risk. No rate is guaranteed to be safe.
Does this include inflation?
No. The FIRE number and time-to-FI estimate are nominal. Entering today's spending unchanged can understate a future nominal target, so stress-test a higher future spending amount separately if you want to account for inflation.
Does this include taxes?
No. Results ignore taxes, trading costs and changes in spending. The projection uses a constant return and a constant contribution rate.
What is the difference between Lean FIRE, Fat FIRE, and regular FIRE?
They describe different retirement spending levels. Lean FIRE means retiring on a tight budget — often $30,000–$40,000/year for a single person, requiring a smaller portfolio ($750k–$1M at 4%) but a more frugal lifestyle. Fat FIRE means retiring with a comfortable or affluent lifestyle — $80,000+/year, requiring $2M+ and a longer accumulation period. Regular FIRE (sometimes called "Chubby FIRE") falls in between, around $40,000–$80,000/year. The right level depends on your desired lifestyle and location — $40,000/year goes much further in a low-cost area than in a major city.
What is Coast FIRE?
Coast FIRE is when you have enough invested that, if you stopped contributing entirely, your existing portfolio would grow to your FIRE number by your target retirement age — thanks to compounding alone. You've "coasted" to the finish line. For example, if you're 35 with $200,000 invested at 7%, it grows to about $1.09M by age 60 — close to a $1.125M FIRE number. Coast FIRE doesn't mean you stop working; it means you can switch to a lower-paying, more enjoyable job or reduce hours, because your existing investments are doing the heavy lifting. Try our Coast FIRE calculator to see if you've reached it.
What are the biggest risks of FIRE?
The biggest risks are: (1) Sequence-of-returns risk — a market crash in the first 5–10 years of retirement can permanently damage your portfolio, especially since FIRE retirements can be 40+ years. (2) Inflation — a 3% inflation rate halves purchasing power in 24 years; your spending needs will rise. (3) Healthcare costs — if you retire before 65, when most people first become eligible for Medicare in the U.S., you need to budget for private health insurance, which can be $10,000–$20,000/year for a family. (4) Tax uncertainty — future tax rates and rules may change. (5) Life changes — having children, supporting family, or unexpected expenses can derail a tight budget. This is why many FIRE planners recommend a 3–3.5% withdrawal rate and a margin of safety.

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Related articles

Aug 26, 2026

How Much Do I Need to Retire?

The two numbers that make a retirement plan — and how the 4% rule works.

Read article →

Related reading

📖 FIRE Movement Guide
Financial independence, retire early — your FIRE number, the 4% rule, and Coast FIRE.→ FIRE, the 4% Rule, and Your FIRE Number
Everything you need to know about calculating financial independence.→ What Is Coast FIRE?
The middle path to financial independence many people overlook.→ How Much Do You Need to Retire?
A framework for calculating your target nest egg.→

Last reviewed: September 2026.

Continue your plan

Use these related resources to put this result in context: FIRE movement guide · 4% rule and FIRE number guide · 4% rule calculator.

The 4% rule is a historical withdrawal framework, commonly studied over 30-year periods. It does not guarantee success or preservation of principal: principal can decline or be depleted. Results depend on allocation, fees, taxes, inflation, retirement length and the sequence of returns.