Find your Coast FIRE number: how much to invest now so growth alone reaches your FIRE number. Checked against every real period since 1928.
Coast FIRE Calculator: When Can You Stop Saving?
Find your Coast FIRE number: how much to invest now so growth alone reaches your FIRE number. Checked against every real period since 1928.
Coast FIRE means you already have enough invested that, left alone, it grows into your full retirement number by retirement age. You can stop adding money and only cover your living costs until then. For 30 to 60, $40,000 a year of spending and a 4% withdrawal rate, the default example needs $138,951 invested today.
Your FIRE number is yearly spending divided by the withdrawal rate. The Coast FIRE number is the FIRE number discounted by the real return over the years left, so it is the amount that grows to the FIRE number by retirement with no more contributions. The default return is the real annualized return of a 100% S&P 500 portfolio from 1928 to 2025, after inflation: 6.8% a year, computed from the data and not assumed. The historical check does not rely on that average. It replays your savings from every real start year that fits the period and counts how many reached the FIRE number.
Sources and method: methodology. To test whether the money lasts once you stop working, use the Monte Carlo retirement calculator.
Built and maintained by Oscar Gallego Ruiz. Historical data through 2025. Methodology and sources.
Disclaimer: Wealth Sim is an independent educational tool for financial simulation and is not affiliated with any financial institution, including Wealthsimple. All calculations are for educational purposes and do not constitute financial advice.
Questions about compound interest and investment calculations
Enter your own numbers. No account required.
Open CalculatorCompare other holding periods, contributions and returns.
See how long your retirement savings last across real S&P 500, bond and inflation years since 1928, plus every historical retirement period.
Estimate your FIRE number and timeline using monthly savings, expected returns, and the 4% rule.
Free S&P 500 calculator: project $10,000 or monthly contributions with dividends reinvested and inflation-adjusted returns.
FIRE number
$1,000,000
$40,000 a year at a 4% withdrawal rate
Coast FIRE number today
$138,951
Invested at age 30, it grows to the FIRE number by age 60
Status
$38,951 to go
You have $100,000 invested today
Your savings at age 60 with no more contributions
$719,677
In today's dollars
Saving $500 a month, you reach Coast FIRE at age 39.
Left untouched from age 30 to 60 (30 years), your current savings would have reached the FIRE number in 19 of 69 real periods starting 1928–1996 (100% stocks). Real growth over those periods ranged from 3.5x to 17.9x.
Assumes a 6.8% real return a year, the 1928–2025 historical real return for this mix.
Source: Damodaran (NYU Stern) and FRED, data through 2025. How the numbers are calculated