To retire at age 50,
you need a FIRE Number of

$1,200,000

Net Worth Progress 0%

$100,000 — FIRE Target

Your Numbers

Current Age

yrs

Target Retirement Age

yrs

Current Net Worth

Monthly Expenses

Monthly Savings / Investments

Advanced Settings

ROI 7.0% · SWR 4.0%

Expected Annual ROI

Safe Withdrawal Rate

The 4% Rule is the historical benchmark. Lower = more conservative; higher = more aggressive.

Asset Projection · Age 35–90

FIRE Number

$1,200,000

Annual exp ÷ SWR

Projected FIRE Age

—

Years to FIRE

—

At current savings rate

Annual FIRE Income

—

Based on your expenses

Quick Start

How to Use This FIRE Calculator

This calculator projects your FIRE Number — the portfolio size that lets your investments cover your living costs indefinitely — and estimates the age you could reach it. Enter five simple figures and the tool models your net worth growing year by year until it crosses the finish line. Here is how to fill in each field.

Start with your Current Age and the Target Retirement Age you are aiming for. The gap between them is your accumulation window — the number of years your money has to grow and compound. The calculator uses this horizon to project your net worth forward and to tell you whether your current pace reaches independence before, on, or after your target. Aggressive targets simply make your savings rate matter more.

Input your Current Net Worth — your invested and liquid assets (retirement accounts, brokerage, cash) minus your debts. This is your starting line. Home equity is sometimes included and sometimes excluded depending on whether you intend to draw on it; for a conservative projection, count only assets you would actually spend down in retirement. The larger your starting base, the more compound growth works in your favour from day one.

Monthly Expenses is the most important number in the model, because your FIRE Number is derived directly from it: annual spending divided by your safe withdrawal rate. Enter what you realistically expect to spend, not a bare-bones figure you can’t sustain. Then enter your Monthly Savings — the amount you invest each month. That contribution, compounded over your accumulation window, is the engine that closes the gap between your net worth today and your FIRE Number.

Open Advanced Settings to set your Expected ROI (a long-run real return of 5–7% is a common, defensible assumption) and your Safe Withdrawal Rate (4% is the traditional benchmark). The results panel then shows your FIRE Number, your projected FIRE age, the years remaining, and your expected annual retirement income, with a chart of net worth crossing the target. Adjust any input — especially expenses and savings — to watch your independence date move.

The FIRE Movement

Frequently Asked Questions

The 4% rule comes from the Trinity Study, which found that a stock-and-bond portfolio could sustain annual withdrawals of 4% of its starting value, adjusted for inflation, for at least 30 years in nearly all historical periods. In practice it means your FIRE Number is roughly 25 times your annual expenses (1 ÷ 0.04 = 25). It is a planning guideline, not a guarantee — many early retirees use a more conservative 3.25–3.5% to account for longer retirements.

Inflation quietly raises the target every year, because the expenses your portfolio must cover keep rising. A lifestyle costing $40,000 today might cost about $54,000 in fifteen years at 2% inflation. The sound way to handle this is to work in real (inflation-adjusted) terms: use a real rate of return — your nominal return minus inflation — so the FIRE Number and projections are already expressed in today’s purchasing power. The 4% rule itself assumes inflation-adjusted withdrawals.

Often, yes. Many costs fall in retirement — commuting, a work wardrobe, payroll taxes, and the savings contributions themselves all disappear once you stop accumulating. Others can rise, particularly healthcare, which is a major consideration for those who retire before government health coverage begins. Model your real expected retirement spending rather than your current spending, and build in a buffer for healthcare and the occasional large, irregular expense.

Your FIRE Number is the amount of invested assets at which the income they generate can cover your living expenses indefinitely, freeing you from needing a paycheque. At a 4% withdrawal rate it equals 25× your annual expenses; at a more cautious 3.33% it becomes 30×. Reaching it does not require you to stop working — it simply means work becomes optional. That optionality is the real prize of the FIRE movement.

Yes. Lean FIRE targets a minimalist budget and a smaller number; Fat FIRE funds a comfortable, higher-spending lifestyle and a much larger one. Coast FIRE is the point where your existing investments will grow into your full number by traditional retirement age with no further contributions, so you only need to cover current expenses. Barista FIRE blends part-time work — often for benefits — with portfolio income. The same math underlies them all; only the expense assumption changes.

Sequence-of-returns risk is the danger that a market crash early in retirement — while you are withdrawing — permanently damages your portfolio, even if average returns later recover. Selling assets in a downturn locks in losses that compounding can’t fully repair. Early retirees manage it by holding one to three years of expenses in cash or bonds, staying flexible on spending in bad years, and sometimes starting with a lower withdrawal rate. It is the single biggest reason the 4% rule deserves a margin of safety.

Deep Dive

The Math Behind Financial Independence

Financial independence is, at its core, a single arithmetic relationship: when the income your assets generate meets or exceeds your expenses, you no longer depend on earned income. Everything the FIRE movement teaches is a way of reaching that crossover point faster. Two forces drive you there — compound interest and your savings rate — and understanding their interplay is what separates a vague wish from a concrete plan.

Compound interest is growth on growth. When your investments earn a return, that return is reinvested and earns its own return the following year, and so on. Over a few years the effect is modest, but over decades it becomes the dominant force in your net worth. A dollar invested at a 6% real return roughly doubles every twelve years; invested early enough, the later-year gains dwarf the original contributions. This is why starting sooner, even with small amounts, is so powerful — you are buying time for compounding to work, and time is the one input you can never add back later.

Yet for anyone pursuing early retirement, the counter-intuitive truth is that your savings rate matters more than your investment return. The reason is twofold. A high savings rate simultaneously shrinks the FIRE Number you need (because you live on less) and accelerates the speed at which you reach it (because you invest more each month). Chasing an extra percentage point of return is uncertain and largely outside your control; raising your savings rate from 15% to 40% is within your control and reshapes your timeline dramatically. The widely cited analysis popularised by Mr. Money Mustache showed that savings rate alone — not income, not market luck — is the primary determinant of how many years it takes to retire. At a 50% savings rate, independence is reachable in roughly seventeen years from a standing start, regardless of income level.

Building a concrete plan, then, comes down to three levers you can actually pull: widen the gap between what you earn and what you spend, invest that gap consistently in low-cost diversified assets, and give compounding the time it needs by starting now. Track your net worth against your FIRE Number, revisit your expense assumptions each year, and keep a margin of safety for inflation and bad market timing. The calculator above turns these principles into numbers specific to your situation — but the strategy itself is refreshingly simple, even if the discipline is not.

This tool and article are for educational purposes only and do not constitute financial advice. Consult a qualified advisor before making investment decisions.