Find your FIRE number, projected years to financial independence, and Coast FIRE threshold. Default assumptions reflect a balanced stock-heavy portfolio.
FIRE number
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Coast FIRE number
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Years to FIRE
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Age at FIRE
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Year-by-year projection
| Year | Age | Portfolio |
|---|
Worked example
Take a 32 year old who spends $60,000 a year, has $100,000 invested, saves $30,000 a year, expects a 5% real return, and uses a 4% safe withdrawal rate with a target retirement age of 60. The FIRE number is annual expenses divided by the withdrawal rate, $60,000 divided by 0.04, which is $1,500,000, equal to 25 times annual spending. Stepping forward year by year, the portfolio takes in $30,000 and then grows 5% each year. It crosses $1,500,000 after 22 years, at age 54, six years ahead of the age-60 target. The Coast FIRE number, the amount that would grow to $1,500,000 by age 60 with no further saving over the 28 remaining years, is $1,500,000 divided by 1.05 to the 28th power, about $382,640. Since the current $100,000 is below that, this saver is not yet coasting, but once the balance passes $382,640 they could stop contributing and still hit FIRE on schedule.
| Item | Value |
|---|---|
| Annual expenses | $60,000 |
| FIRE number (expenses / 4%) | $1,500,000 |
| Coast FIRE number (today) | $382,640 |
| Years to FIRE | 22 |
| Age at FIRE | 54 |
How it is calculated
FIRE planning rests on the safe withdrawal rate from the Trinity Study, which found a portfolio could sustain inflation-adjusted withdrawals of about 4% a year for 30 years with a high success rate. Inverting that, your FIRE number is annual expenses divided by your chosen withdrawal rate, so a 4% rate means saving 25 times your spending and a more conservative 3.5% rate means about 29 times. The tool then steps your portfolio forward one year at a time, adding your annual savings and applying your expected real return, and reports the year the balance first reaches the FIRE number. Because the inputs are real, inflation-adjusted, the result is in today's purchasing power. Coast FIRE is the balance that would compound to your FIRE number by your target age with zero further contributions, a useful milestone because once you reach it your existing savings alone finish the job.