Coast FIRE Calculator (2026)
Find out if your current savings alone, with no further contributions, will grow to your retirement number by your target retirement age.
Your numbers
At this contribution rate, you're not projected to reach Coast FIRE before age 65 — you'd still be actively saving for retirement right up to that age, which is a normal FIRE trajectory, just not a “coasting” one.
Projected savings vs. coast number
Assumes you keep contributing $500/mo. Blue = already coasted by that age.
Estimate only. All figures are in today's dollars — the return rate should be a real (after-inflation) rate, and retirement spending is assumed constant in real terms, which is the standard simplification most FIRE calculators use to avoid separately modeling inflation. Assumes a constant return every year (no market volatility), doesn't account for Social Security, and doesn't model taxes on withdrawals. Not financial advice.
Frequently asked questions
Q.What does the 4% rule actually say?
It comes from William Bengen's October 1994 article in the Journal of Financial Planning. Bengen tested every retirement start year since 1926 against historical stock, bond and inflation data (Ibbotson Associates' 1992 yearbook) for a portfolio that was half intermediate-term Treasury notes and half common stocks, held in a tax-deferred account. Withdrawing 4% of the starting balance in the first year, then the same dollar amount adjusted for inflation each year, never exhausted the portfolio before 33 years in any starting year he tested, and in most it lasted 50 years or more. His own test was a minimum of 30 years, and he advised clients to withdraw no more than 4% in the early years, especially if they retire at 60 or younger.
So the rule is a historical 30-year finding, not a guarantee and not a promise to last forever. For a retirement much longer than 30 years, or a different mix of investments, the safe rate may be lower; this calculator lets you change the withdrawal rate to see what that does to your number. The FIRE number here is your yearly spending divided by that rate ($60,000 at 4% is $1,500,000).
To see how the rule held up in every 30-year window since 1928, rather than in Bengen's original sample, read the 4% rule through every 30-year retirement since 1928, or replay your own plan against each start year with the retirement withdrawal calculator.
Q.What return should I enter?
Enter a real (after-inflation) return, because everything here is in today's dollars. The calculator starts at 7%, which is about what stocks alone returned after inflation in the data Bengen used: his article cites 10.3% a year for common stocks and 5.1% for intermediate-term Treasuries against 3% inflation, which makes a 60/40 mix about 5% after inflation. A lower real return makes the coast number much larger: with $60,000 of spending and a 4% withdrawal rate, the number you need today to coast for 35 years is $140,494 at a 7% real return and $271,935 at 5%.
Bengen also warns that averages are a poor guide to withdrawals: it was a severe stock decline early in retirement, together with high inflation, that set the safe rate, not the average return. The calculator uses one constant return every year, so it cannot show that risk.
Q.If I have reached my coast number, can I stop saving?
For retirement saving only, and only if the assumptions hold. You still need income to live on until you retire; the estimate leaves out taxes on withdrawals (Bengen's portfolio was tax-deferred, so capital gains tax was not part of his test), Social Security, healthcare costs before Medicare, and any market volatility. Treat the result as a way to see how much your current balance can do over time, and check the assumptions against your own situation. This is not financial advice.