FIRE (Financial Independence, Retire Early) Calculator
Calculate your (Financial Independence, Retire Early) number and how long until financial independence.
What this calculator does
This FIRE calculator models a single investment pot, the kind held in a taxable brokerage account, and runs it through two phases. It accumulates your contributions at your expected return until your desired retirement age, then stops contributions and starts withdrawing your chosen spend level, raised each year with inflation, from the actual compounding balance.
Because it simulates the drawdown rather than stopping at a target, it answers the question most FIRE calculators skip: not just when you first touch a number, but whether the money survives. If the balance reaches zero before 95 the calculator reports the age it happens, which is usually more informative than the target itself.
When to use it
Use it when you are choosing between lifestyles rather than chasing one number. Switching between Lean, Traditional, Fat, Barista and Coast re-runs the entire simulation at that spend level, so you can see how many years of work separate a frugal early exit from a comfortable one.
It is also the tool for the Coast question, which is worth asking far earlier than most people do. If your existing balance already coasts to Traditional FIRE by your access age, your decision changes shape entirely: further saving buys earlier freedom, not eventual security. And the lump sum field lets you model a known future windfall landing at a specific age.
Understanding the inputs
Current savings should be money you can genuinely reach before 59 and a half, since the withdrawal phase begins at your desired retirement age. Expenses drive four of the five FIRE types directly, so use your real annual spending rather than your income; the difference between those two numbers is the entire plan.
Retirement account access age exists only for Coast FIRE and defaults to the penalty-free threshold. Expected return and inflation together set your real return, which discounts every target, so treat the gap between them as the important number. Barista part-time income should be after tax, because it is subtracted from spending you would otherwise fund from the portfolio.
How is this calculated?
Each FIRE target is the present value of that lifestyle's annual spend, drawn every year of retirement and rising with inflation, discounted at your expected real return (your return net of inflation) — not a flat 4% rule, which is a pension drawdown convention that doesn't apply to a self-managed brokerage pot. The projection itself accumulates until your desired retirement age, then switches to withdrawing that spend level (inflation-adjusted) from your actual balance, so you can see whether the money really lasts.
A worked example
Take a 32-year-old with $120,000 invested, adding $2,000 a month at 7 percent with 2.5 percent inflation, spending $60,000 a year and aiming to retire at 50. The pot reaches roughly $1,283,000 by 50. The Traditional target, the present value of $60,000 a year to 95 at a 4.4 percent real return, is about $1,169,000, so the plan clears.
Switch to Fat FIRE at $78,000 a year and the target jumps to roughly $1,520,000, which the same pot misses. Run the drawdown and the balance hits zero at around age 82. Lean FIRE at $42,000 needs only about $818,000 and could have been reached years earlier.
Limitations and assumptions
Every figure here is a projection under assumptions, not a prediction. The model applies one flat return each year and no market volatility, so it cannot represent sequence-of-returns risk, which is the dominant danger in early retirement. Two portfolios with identical average returns can end in very different places depending purely on when the bad years arrive.
It also assumes tax-advantaged withdrawals are tax-free, ignores capital gains tax on a brokerage pot, holds contributions and spending constant, and uses a fixed horizon of 95. The depletion age is the honest output here: treat it as a warning signal rather than a date.
Common Questions
- Why does this not use the 4 percent rule?
- Because the 4 percent rule is a drawdown convention built around a 30-year retirement, and early retirement is longer than that. This calculator instead prices each target as the present value of a level real spend running to age 95, discounted at your own real return. Retiring at 45 and at 60 produce genuinely different numbers.
- So what is my FIRE number here?
- It is the lump sum that, growing at your real return, funds your chosen spend level every year until 95 with the last dollar leaving at the end. Because it discounts at your return net of inflation, a higher assumed return lowers the target and higher inflation raises it. Both effects are real and both are shown.
- What do the five FIRE types mean?
- Lean covers 70 percent of your current expenses, Traditional covers 100 percent, and Fat covers 130 percent. Barista covers your expenses minus the part-time income you expect to keep earning. Coast assumes you stop contributing today and let existing growth carry you to Traditional by your retirement account access age.
- Does picking a type only change the target number?
- No, it drives the whole simulation. Selecting Fat FIRE does not just raise the target; it also makes the withdrawal phase draw 130 percent of your expenses every year, inflation-adjusted. That means each type produces its own accumulation path, its own drawdown, and its own answer to whether the money actually lasts.
- What is Coast FIRE and why does access age matter?
- Coast FIRE asks whether what you already hold, with no further contributions, will grow into a Traditional FIRE number by the age you can reach your 401(k) and IRAs without penalty, normally 59 and a half. If it does, every dollar you save from now on buys earlier retirement rather than eventual retirement.
- What does the portfolio depletion warning mean?
- It means the simulation ran your balance forward through the withdrawal phase and it hit zero before age 95. Reaching a target number on paper is not the same as the plan surviving, because withdrawals rise with inflation while returns are flat. If you see a depletion age, contribute more, spend less, or choose a leaner type.
- Should I include my 401(k) in current savings?
- Only cautiously. This models a single brokerage-style pot you can draw from at any age, which is why the withdrawal phase starts at your desired retirement age rather than 59 and a half. Money locked in a 401(k) or IRA is not available before then without a 72(t) schedule, the Rule of 55, or a Roth conversion ladder.
- How do I fund the years before 59 and a half?
- That gap is the central problem in US early retirement. Common bridges are a taxable brokerage account, a Roth conversion ladder where converted amounts become accessible after five years, substantially equal periodic payments under section 72(t), and the Rule of 55 for a 401(k) at the employer you leave at or after 55.
- What return and inflation should I enter?
- Six to seven percent nominal is a reasonable long-run figure for a diversified equity portfolio after fees, with inflation at 2.5 to 3 percent. What matters is the gap between them, since the real return is what discounts your target. Moving real return from 4 percent to 3 percent raises a Traditional target considerably.