How long does it take to reach financial independence? Points Frog's FIRE calculator shows that the answer depends less on income than on the share of it you save. Starting from nothing, saving 50% of take-home pay reaches financial independence in about 17.5 years at a 4% return after inflation. Saving 10% takes about 58 years.
A higher savings rate works twice. More money goes in, and you are living on less, so there is less spending to replace. Starting from zero, how much you earn doesn't change the years. The share you save does.
FIRE stands for financial independence, retire early. Your FIRE number is the amount you need invested to live off your portfolio for good: your yearly spending divided by your withdrawal rate. At the common 4% rate, that is 25 times spending, so $40,000 a year needs $1,000,000.
A worked example
The calculator opens on a 30-year-old who spends $50,000 a year, has $50,000 invested and adds $30,000 a year. That is a savings rate of 37.5% of $80,000 in take-home pay.
Their FIRE number is $1,250,000. At a steady 4% return after inflation, they reach it at 53, in about 23.2 years. If returns match the S&P 500's 6.8% average after inflation since 1957, they reach it at 48.
The calculator shows three other targets for the same person, all at the steady return:
- Lean FIRE, living on $40,000 a year, needs $1,000,000. They would reach it at 49.
- Fat FIRE, living on $100,000 a year, needs $2,500,000. They would reach it at 65.
- Coast FIRE is $316,769. Invested now, that sum would grow to $1,250,000 by 65 with no more saving. At their current pace they reach it at 41.
What moves the answer most
The savings rate matters most. Holding a 4% withdrawal rate and starting from $0, the page's table shows:
| Savings rate | Steady (4%) | S&P 500 (6.8%) |
|---|---|---|
| 10% | 58.3 years | 42 years |
| 30% | 30.4 years | 24 years |
| 50% | 17.5 years | 14.8 years |
| 70% | 9 years | 8.2 years |
The withdrawal rate comes next. The 4% rule comes from William Bengen's 1994 research on 30-year retirements, but retiring at 40 can mean 50 years or more of withdrawals. Early Retirement Now's research found that over 60 years, 4% a year from a portfolio half in stocks and half in bonds ran out about 35% of the time in US market history. It called 3.5% the new 4%. Fidelity suggests saving 33 times your expenses, a 3% rate, to retire before 62. Morningstar's forward-looking research puts the safe starting rate at 3.9% for a 30-year retirement beginning in 2026.
Each step down raises the target. For $40,000 a year, the FIRE number is $1,000,000 at 4%, $1,142,857 at 3.5% and $1,333,333 at 3%. The page notes that spending a little less after bad market years makes any of these rates safer.
The return matters too, and the calculator lets you change both its steady and optimistic rates. It checks Coast FIRE at the steady rate, since coasting leans hardest on future returns.
What the calculator leaves out
The page calls itself an educational estimate, not financial advice. It leaves out taxes, investment fees, health insurance before Medicare at 65, and changes in your income or spending. Markets can return less than either case.
Retiring early also raises questions the calculator does not model. Money taken from a 401(k) or IRA before age 59½ usually owes a 10% additional tax on top of income tax, though the IRS lists exceptions. Social Security retirement benefits start at 62 at the earliest, reduced by up to 30%. The page calls leaving them out of a FIRE number the cautious choice.
Where the figures come from
The 6.8% optimistic return is the S&P 500's average with dividends reinvested since 1957, after inflation, from Robert Shiller's data. The Lean and Fat FIRE lines of $40,000 and $100,000 a year follow The Motley Fool's guide to the types of FIRE, dated July 26, 2025. The savings-rate idea was popularized by Mr. Money Mustache's 2012 post, which assumed a 5% return after inflation. The calculator uses its own two returns instead. All figures are in today's dollars, and the page's figures were checked in October 2026.
Use it on your own site
The FIRE calculator is free to embed on a blog or site with copy-and-paste code, with no ads or tracking. See how to embed it.
Source: Early Retirement Now, The ultimate guide to safe withdrawal rates, December 7, 2016; Fidelity, What is fat FIRE?, May 1, 2025; The Motley Fool, 4 types of FIRE, July 26, 2025; Morningstar, safe withdrawal rate for 2026; S&P 500 returns since 1957, from Robert Shiller's data. Checked October 2026. Figures are educational estimates, not financial advice.