Retirement calculator

Free early retirement (FIRE) calculator

Find out when you can retire early. Enter your age, current savings, income, and expenses, then pick a safe withdrawal rate. The calculator returns your FIRE number (25× expenses at 4%), your savings rate, and the age you reach financial independence — updated live, as you type.

On this page13 sections

InputsLive

Current age

years

Current savings (invested)

Annual income

Annual expenses

Real return

Safe withdrawal rate

Result

Age at financial independence

45.4

The age you reach financial independence — about 15.4 yrs from now, once your portfolio hits $1,000,000.

FIRE number$1,000,000

Savings rate50%

Years to FI15.4 yrs

Estimates only, based on a constant real return and steady saving. Not financial advice.

Results are estimates. Consult a professional.

Definition

What an early retirement (FIRE) calculator does

An early retirement calculator answers the one question at the heart of the FIRE movement — Financial Independence, Retire Early: given what you earn, what you spend, and what you have already saved, how many years until you can stop working, and at what age? It turns the abstract goal of financial independence into two concrete numbers — a target portfolio (your FIRE number) and a date — and recomputes both the moment you change an input.

The engine rests on two well-documented ideas. The first is the 4% rule: a portfolio of roughly 25× your annual expenses can fund an indefinite retirement, because withdrawing 4% a year (1 ÷ 0.04 = 25) survived every historical 30-year period in the studies that defined it. The second is that your savings rate — the share of income you keep rather than spend — is the dominant lever on how soon you arrive. This calculator combines both.

Financial Independence, Retire Early — saving aggressively to reach a portfolio that covers your living costs for life.

The target portfolio that makes you financially independent: annual expenses ÷ safe withdrawal rate (25× expenses at 4%).

The fraction of your income you save: (income − expenses) ÷ income. The single biggest driver of how soon you retire.

The percentage of the starting portfolio you can withdraw each year (inflation-adjusted) without running out — classically 4%.

Investment return after subtracting inflation. Using a real return keeps every figure in today's dollars.

Formula

The early-retirement formula

Two formulas do all the work. The first sets the target; the second finds the time to reach it.

FIRE number = annual expenses ÷ withdrawal rate = expenses × (100 ÷ rate%)

savings rate = (income − expenses) ÷ income

(1 + r)^n = (FIRE × r + annual savings) ÷ (current savings × r + annual savings)

years to FI (n) = ln[ (FIRE × r + savings) ÷ (current × r + savings) ] ÷ ln(1 + r)

age at FI = current age + n

The third line is the future-value equation solved for time. Your portfolio each year is last year's balance grown by the return, plus a year of fresh savings; setting that growing balance equal to the FIRE number and solving for the exponent gives a closed-form answer — no trial and error. Because the return is real, the FIRE number stays in today's dollars and you never have to inflate your expenses forward.

At a 4% withdrawal rate the multiple is exactly 25×. Drop to 3.5% and it rises to about 28.6×; at a more conservative 3% it becomes 33.3×. A lower withdrawal rate is safer but demands a larger portfolio — the calculator's toggle shows the trade-off instantly.

Method

How to calculate your FIRE number and retirement age

Whether you use the calculator above or a spreadsheet, the path to financial independence comes together in five steps:

Find your annual expenses. Your spending — not your income — sets the finish line. Use what you expect to spend in retirement, in today's dollars.
Pick a withdrawal rate. 4% is the classic; 3–3.5% is more conservative for a long early retirement. Your FIRE number is expenses ÷ that rate.
Work out your savings rate. Subtract expenses from income to get annual savings, then divide by income. A 50% savings rate means you keep half of what you earn.
Set a real return. Use an after-inflation figure — historically about 4–7% for a diversified stock-and-bond portfolio. This keeps the answer in today's money.
Solve for the years. The calculator applies the formula above to your current savings, annual savings, and real return, then adds the result to your age to give your FI age.

Worked example

A worked example using the early retirement calculator

Example: a 30-year-old saving half their income

Sam is 30, has $50,000 invested, takes home $80,000 a year, and spends $40,000. They expect a 5% real return and plan around the 4% rule. Here is how the calculator walks through it.

Step 1 — Savings rate and FIRE number

Sam saves $80,000 − $40,000 = $40,000 a year, a savings rate of 40,000 ÷ 80,000 = 50%. The FIRE number is the $40,000 of expenses divided by the 4% withdrawal rate: 40,000 ÷ 0.04 = $1,000,000 — exactly 25× expenses.

Step 2 — Solve for the years

(1.05)^n = (1,000,000 × 0.05 + 40,000) ÷ (50,000 × 0.05 + 40,000)

(1.05)^n = 90,000 ÷ 42,500 = 2.1176

n = ln(2.1176) ÷ ln(1.05) = 15.38 years

Step 3 — Read the result

Financially independent at age 45.4

Sam reaches the $1,000,000 FIRE number in about 15.4 years, at roughly age 45 — fifteen years and change after starting. The calculator shows the FIRE number, the 50% savings rate, and the years to FI side by side, all in today's dollars.

What if Sam had started from zero? With no existing savings, the same 50% rate and 5% return would take about 16.6 years instead of 15.4 — the $50,000 head start is worth a little over a year. All figures here are produced by this calculator using the formula above.

The big lever

How your savings rate sets your retirement date

The most striking insight of the FIRE movement is that your savings rate, not your income, decides how soon you retire. A high savings rate works twice: it fills the portfolio faster and proves you can live on less, which shrinks the FIRE number you need. The table below assumes a zero starting balance and a 5% real return, with the FIRE number set to 25× expenses (the 4% rule).

Savings rate	Years to financial independence
10%	51.4
20%	36.7
30%	28.0
40%	21.6
50%	16.6
60%	12.4
70%	8.8

Years to FI from a zero starting balance, 5% real return, 4% withdrawal rate. Figures computed by this calculator.

Doubling your savings rate from 30% to 60% does not just halve the wait — it cuts it from 28 years to 12. The relationship is steeply non-linear because higher saving raises contributions and lowers the target at the same time. Any current savings you already hold shortens these times further.

Variants

Lean FIRE, Fat FIRE, Coast FIRE and Barista FIRE

FIRE is not one-size-fits-all. The same math produces very different targets depending on the lifestyle you plan around and how you bridge to it:

Lean FIRE — a frugal early retirement, often under ~$40,000 a year of spending. A smaller FIRE number, reached sooner, with less margin for surprises.
Fat FIRE — a comfortable, higher-spend retirement. A much larger FIRE number that takes longer but leaves room for travel, family, and the unexpected.
Coast FIRE — you save enough early that, with growth alone, the portfolio reaches your FIRE number by traditional retirement age. You stop adding new money and let compounding coast.
Barista FIRE — you cover part of your costs with light or part-time work, so a smaller portfolio is enough to fill the rest.

Each is the same calculation with a different expense figure or a different bridge to full independence. Model your own number here, then compare it against a full retirement projection or check what portfolio your spending implies with the retirement income calculator.

Gotchas

What the simple math leaves out

The 4% rule and a single average return make early retirement legible, but real life is messier. Keep these caveats in view:

Sequence-of-returns risk. A market crash in your first few retirement years does far more damage than the same crash later. The 4% rule was built to survive bad sequences historically, but it is not a guarantee.
A 30-year horizon, not 50. The studies behind the 4% rule tested 30-year retirements. Retiring at 40 means funding 50+ years, which is why many in the FIRE community use 3–3.5% instead.
Constant spending is an assumption. Health costs, children, and lifestyle creep all move your expenses — and your FIRE number — over time.
Taxes and fees are excluded. The model is gross. Account fees, investment costs, and taxes on withdrawals all reduce what you actually keep.
Healthcare before Medicare. US early retirees must self-fund health insurance until age 65, a cost that belongs in your expense figure.

Treat the result as a planning baseline, not a promise. Bengen and the Trinity authors both framed the withdrawal rate as a matter of planning under uncertainty — expect to revisit your number as markets, spending, and life change.

Reference

Key terms, defined

The point where your investments can cover your living expenses indefinitely, making paid work optional.

Shorthand for the 4% rule: save 25 times your annual expenses and you can withdraw 4% a year.

The share of your starting portfolio you draw down each year, increased with inflation thereafter.

The danger that poor returns early in retirement permanently shrink a portfolio you are also withdrawing from.

Having saved enough that growth alone reaches your FIRE number by a target age, with no further contributions.

Methodology

Sources and methodology

The 4% rule originates with financial planner William Bengen, whose 1994 study found that an initial 4% withdrawal, adjusted for inflation, survived at least 30 years across every historical period he tested using U.S. stock and bond returns. The Trinity Study (Cooley, Hubbard & Walz, 1998) reproduced and extended that finding in the AAII Journal, reporting that 3–4% withdrawal rates produced high success rates for stock-heavy portfolios. This calculator uses the resulting 25× (and 28.6× / 33.3×) multiples for its FIRE number, and solves the standard future-value equation in closed form for the years to reach it.

W. P. Bengen (1994), "Determining Withdrawal Rates Using Historical Data," Journal of Financial Planning — the origin of the 4% rule.Cooley, Hubbard & Walz (1998), "Retirement Savings: Choosing a Withdrawal Rate That Is Sustainable," AAII Journal — the Trinity Study.Trinity study — overview of authors, publication, and the 4% withdrawal finding.

Questions

Frequently asked questions about the free early retirement (FIRE) calculator

An early Retirement (FIRE) calculator is a free online tool that helps you find the years until you can retire early and the age you reach financial independence, from your savings rate, current savings, and expected real return — plus your FIRE number (25× expenses). Your FIRE number is the portfolio that makes work optional: annual expenses divided by a safe withdrawal rate (25× expenses at 4%). The years to reach it solve the future-value equation for time, using your current savings, annual savings, and expected real return. It runs entirely in your browser with instant results and no sign-up.

Multiply your annual expenses by 25 — that is your FIRE number under the 4% rule. If you spend $40,000 a year, you need about $1,000,000 invested. Spending sets the target, not income: two people earning very different salaries but spending the same amount need the same portfolio. For a longer early retirement, many use 3–3.5%, which raises the multiple to roughly 28.6× or 33.3×.

Your FIRE number is the portfolio that can fund your living costs indefinitely. Calculate it by dividing your annual expenses by your safe withdrawal rate: at 4%, that is expenses ÷ 0.04 = 25× expenses. The calculator above does this live and also shows how many years of saving it takes to get there.

The 4% rule says you can withdraw 4% of your starting portfolio in your first year of retirement, then adjust that dollar amount for inflation each year, with a high chance of never running out over 30 years. It comes from William Bengen's 1994 study and the 1998 Trinity Study, which tested it against historical U.S. stock and bond returns. Withdrawing 4% is the mirror image of saving 25× expenses.

It is a starting point, not a guarantee. The studies behind it tested 30-year retirements; retiring at 40 may mean funding 50 years or more, so many in the FIRE community use a more conservative 3–3.5% withdrawal rate and a flexible spending plan. Sequence-of-returns risk — a market crash early in retirement — is the main danger the simple rule does not fully capture.

Your savings rate is the biggest lever. From a zero starting balance at a 5% real return, a 30% savings rate reaches financial independence in about 28 years, 50% in about 17 years, and 70% in under 9 years. Higher saving works twice — it builds the portfolio faster and lowers the expenses you need to cover — which is why the years fall so steeply as the rate rises.

About

About this early retirement (FIRE) calculator

This early retirement calculator runs entirely in your browser. Every figure you enter stays on your device — nothing is sent to a server, logged, or shared. It derives your FIRE number from your expenses and withdrawal rate, then solves the future-value equation for the years until your savings reach it, updating instantly as you type.

Calculators Cloud offers 400+ free tools with no sign-up. The whole Retirement calculators shelf includes Savings rate, Retirement nest egg, and Retirement income tools alongside this one. Or browse the full calculator directory.