Retirement

FIRE Calculator

Financial independence means having enough invested that work becomes optional. Your FIRE number is the nest egg whose safe withdrawals cover your spending — the 4% rule puts it at about 25× your annual expenses. Enter your numbers to see the target and your timeline.

Formula shown below · Tested against worked examplesHow we verify

Annual expenses in retirement

Safe withdrawal rate

Current invested savings

Monthly contribution

Expected annual return

A real (after-inflation) return keeps the target in today's dollars.

Your FIRE number

$1,000,000

The nest egg that funds your spending at a 4% withdrawal rate.

Progress to FI: 25%
Time to financial independence: 10 years 7 months

Compare scenariosTry three values of one input

Vary

FIRE Calculator results for three values of Annual expenses in retirement
Annual expenses in retirement
Your FIRE number	$900,000	$1,000,000+$100,000	$1,100,000+$200,000
Progress to FI	27.78%	25%−2.78%	22.73%−5.05%
Time to financial independence	9 years 6 months	10 years 7 months+1 year 1 month	11 years 7 months+2 years 1 month

Every other input stays at the value you set above — currently $40,000 for annual expenses in retirement. Differences are measured against the first column.

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How this calculator works

FIRE number = annual expenses ÷ safe withdrawal rate (4% → 25×). Time to FI projects your current savings plus monthly contributions at the expected return until the balance reaches the target; progress is current savings ÷ FIRE number, capped at 100%.

This assumes level contributions, a constant return, and steady expenses. Real markets and sequence-of-returns risk matter enormously near retirement, and the 4% rule is a guideline, not a guarantee — treat the timeline as a planning estimate and revisit it as your numbers change.

Formula

FIRE number = Annual expenses ÷ w

At w = 0.04 this is 25 × annual expenses

w: Safe withdrawal rate, as a decimal
Annual expenses: What the portfolio must fund, after Social Security or any pension

The 4% rule was derived from historical US 30-year retirements. A 40-year retirement argues for a lower rate, which raises the multiple — 3.5% implies about 28.6 × expenses rather than 25.

What this assumes

The 4% rule, derived from historical US 30-year retirements. A 40-year retirement argues for a lower rate and therefore a larger target.
Spending stays constant in real terms. Real retirements are rarely flat — early years often cost more.
Healthcare before Medicare eligibility at 65 is not modelled, and is the most underestimated cost of retiring early.

What changes this number

Target annual spending: The target is a multiple of it, so every $10,000 less to spend removes about $250,000 from what you must accumulate.
Withdrawal rate assumed: Moving from 4% to 3.5% raises the target by roughly a seventh. Over a long retirement that caution is defensible.
Savings rate: Decides the date. At high savings rates the arithmetic is dominated by what you save, not what you earn.

A worked example

Take the $40k spend, 4% rule scenario. These figures are produced by the calculator above, not written alongside it, so they always match what the tool returns.

What you enter

Annual expenses in retirement: $40,000
Safe withdrawal rate: 4% (classic, 25×)
Current invested savings: $250,000
Monthly contribution: $3,000

What it returns

Your FIRE number: $1,000,000
Progress to FI: 25%
Time to financial independence: 10 years 7 months

Sources

This calculator uses no external data — the result follows entirely from the formula above and the values you enter, so there is nothing to cite beyond the arithmetic.

Calculator last reviewed August 9, 2026. How we verify

Try an example

$40k spend, 4% rule Lean FIRE ($30k)Conservative 3.5%

Frequently asked questions

What is a FIRE number?

Your FIRE (Financial Independence, Retire Early) number is the amount you need invested so that safe withdrawals cover your living expenses indefinitely. Using the 4% rule, it's about 25 times your annual spending — spend $40,000 a year and your FIRE number is roughly $1 million, on top of any pension or Social Security.

What is the 4% rule?

The 4% rule says you can withdraw 4% of your starting portfolio in year one, adjust for inflation each year after, and the money has historically lasted at least 30 years in most market scenarios. Flip it around and 4% withdrawals require 25× your annual expenses. A lower rate (3–3.5%) is safer for very long or early retirements.

Should I use a real or nominal return?

Use a real (after-inflation) return — roughly your expected return minus about 3% — so the FIRE number and timeline stay in today's dollars. If you use a nominal return, your target should grow with inflation too. Keeping everything in real terms is simpler and avoids overstating your progress.

What are Coast FIRE and Barista FIRE?

Coast FIRE is having enough invested that, without adding another dollar, it will grow to your FIRE number by traditional retirement age — so you only need to cover current expenses. Barista FIRE is partial independence: enough savings that a part-time job (often for benefits) covers the gap. Both are milestones on the way to full FIRE.

This calculator helps answer

How much do I need to retire?

Turn the spending you want into a number, check whether your current saving reaches it, and see what Social Security and a later claiming age take off the total.