Financial independence (FI) is the point where your invested savings can cover your living expenses forever, and work becomes a choice rather than a requirement. This calculator turns that abstract goal into three concrete numbers: your FIRE number (the nest egg you need), your progress percent (how far along you are today), and the estimated years left until you can stop working.
It is built on the Trinity Study 4% rule: if your annual spending is 4% or less of your investment portfolio, a 60/40 stock/bond mix has historically lasted 30-plus years through every market cycle. That means your FIRE number is simply 25 times your annual spending. Adjust the sliders below and every figure updates instantly.
How to Use
- Enter your Current Net Worth — the total dollars you have already invested in retirement accounts, brokerage accounts, and savings. Do not count your primary residence; FI needs liquid, invested assets.
- Set your Annual Spending in Retirement. Be realistic: estimate your real yearly expenses once you leave work, adjusted for inflation. If you currently spend $40,000, type $40,000.
- Enter your Annual Savings Added — the extra dollars you will invest each year between now and FI. A higher savings rate is the single biggest lever you control.
- Set your Expected Annual Return. Use a real (after-inflation) number. 7% is the classic long-run US stock/bond average; 5% is a more conservative stress test.
- Optionally adjust the Safe Withdrawal Rate. 4% is the Trinity Study default (25x spending). More conservative people use 3.5% (28.5x); aggressive people use 4.5% (22x).
The result card then shows your FIRE number, your current progress toward it, the dollar gap still to close, the years until you hit 100% at your current savings pace, and the safe monthly income your portfolio already produces today.
The Math Behind the Number
The FIRE rule is shockingly simple:
FIRE number = annual spending ÷ safe withdrawal rate
At the 4% rule, that is annual spending × 25. Spend $40,000 a year and you need $1,000,000. Spend $80,000 and you need $2,000,000. Notice that the FIRE number scales directly with spending — cutting your expenses by $10,000 a year lowers your required nest egg by $250,000, which is why the FI community treats low expenses as both a lifestyle choice and a math shortcut.
Your progress percent is your current net worth divided by your FIRE number. A $600,000 portfolio against a $1,000,000 target puts you at 60% FI. That number is the single most motivating figure on the page: it turns "am I saving enough?" into a measurable bar that climbs every year.
Years to FI is solved from the standard future-value annuity equation:
NW × (1 + r)ⁿ + Savings × ((1 + r)ⁿ − 1) / r = FIRE number
Where NW is your current net worth, r is your annual real return, and n is the number of years until FI. The engine solves for n directly. With a $600,000 portfolio, $40,000 annual spending, $30,000 yearly savings, and a 7% real return, you hit $1,000,000 in roughly 4.9 years.
Examples
Example 1 — The classic early-retiree. A 38-year-old teacher has saved $600,000, expects to spend $40,000 a year in retirement, saves $30,000 a year, and earns a 7% real return. Her FIRE number is $40,000 ÷ 0.04 = $1,000,000. Her current progress is 60%, and she reaches 100% in about 4.9 years — age 43. At that point her portfolio throws off $40,000 a year (about $3,333 a month) without ever touching principal.
Example 2 — Starting from zero. A 25-year-old earns $70,000, spends $35,000, and saves $35,000 a year. Her FIRE number is $35,000 ÷ 0.04 = $875,000. With no current savings but a 7% real return, the annuity formula puts her at FI in roughly 16 years — age 41. This is the math that makes the "mythical 30-something retiree" plausible: it is not magic, it is a 50% savings rate.
Example 3 — Already financially independent. A household with $2,000,000 in investments and $80,000 of planned annual spending has a FIRE number of $2,000,000. Progress is 100%, the gap is $0, and years to FI is 0. The calculator flags that they can stop working today and withdraw $6,667 a month under the 4% rule.
FAQ
What is a FIRE number?
Your FIRE number is the total investment portfolio you need so that annual withdrawals at your chosen safe withdrawal rate cover your living expenses forever. At the classic 4% Trinity Study rate, it equals 25 times your annual spending. Spend $50,000 a year and your FIRE number is $1,250,000.
How is financial independence progress calculated?
Progress to FI is your current net worth divided by your FIRE number, expressed as a percentage. If you have $450,000 invested and your FIRE number is $1,000,000, you are 45% financially independent. Each dollar you save moves the bar forward; investment returns compound the effect.
What is a good safe withdrawal rate?
The Trinity Study popularized 4% of the first-year portfolio balance, adjusted for inflation thereafter, as a rate that survived every 30-year US retirement period since 1926. Conservative planners now use 3.5% (about 28.5x spending), while early retirees who expect a 50-60 year horizon often drop to 3.0-3.25%.
Does my house count toward net worth?
Usually no. A primary residence does not throw off cash flow, and you cannot spend it without moving or taking out a reverse mortgage. This calculator asks for investable net worth — 401(k), IRA, brokerage, HSAs, and cash. Counting your house inflates the percent progress and gives a falsely optimistic FI date.
How much should I save each year to retire early?
There is a direct relationship between savings rate and time to FI. A 10% savings rate implies decades of work; a 50% savings rate cuts the working career to roughly 15-17 years; a 70% savings rate can get you there in under 10 years. Use the Annual Savings slider above to see how each additional $10,000 per year pulls your FI date earlier.
What return should I assume?
Use a real, inflation-adjusted number. A diversified US stock/bond portfolio has averaged about 7% real over the last century, but future decades may be lower. Run a 5% scenario as a stress test and an 8% scenario as an upside case; if your FI date is comfortable across all three, your plan is robust.
What if I already have enough to retire?
If your net worth is at or above your FIRE number, this calculator reports 100% progress, a zero dollar gap, and zero years to FI. That means your portfolio already generates your desired annual income under your chosen withdrawal rate — work is now optional.
Disclaimer
This financial independence calculator is provided for informational purposes only and does not constitute financial, tax, or investment advice. The FIRE number, progress percent, and projected years are estimates based on the Trinity Study 4% rule and assumed constant returns; actual market returns, inflation, taxes, and spending will vary. Past performance does not guarantee future results, and early retirement carries sequence-of-returns risk that a simple annual model does not capture. Always build an emergency fund, consider healthcare costs before Medicare age, and consult a licensed fiduciary advisor before making a major retirement decision.