Determine if you've saved enough for early retirement to let compound interest do the heavy lifting from today.
Coast FIRE (Coasting Financial Independence, Retire Early) is a milestone within the early retirement community where you have accumulated enough money in your investments that you no longer need to save another dollar for retirement. From this point forward, compound interest alone will passively grow your portfolio to fully fund your target lifestyle by your retirement age.
Hitting Coast FIRE represents a massive psychological release. It means you can stop contributing to your 401(k), IRAs, or index funds and instantly shift to covering only your immediate living expenses. You can take a lower-paying but more fulfilling job, scale back to part-time hours, start a business, or work in a field you truly enjoy without worrying about saving for future security.
The calculation uses a simple two-step mathematical formula. First, you calculate your absolute Full FIRE Target Number. Then, you discount that number back to the present day based on expected investment returns.
Coast FIRE relies heavily on compound interest over a long time horizon. Since the market fluctuates, using a conservative real growth rate is critical. Most financial analysts recommend using a 5% real growth rate (which assumes a 7.5% nominal return and 2.5% inflation) as a safe baseline. If you are closer to retirement, you have less time for market averages to smooth out, so you should be even more conservative.
No. Coast FIRE is distinct from traditional Full FIRE. Traditional FIRE means you can quit working today because your investments can support your current spending. Coast FIRE means your retirement is fully funded for a future age, but you still need to work right now to cover your day-to-day living costs until you reach that retirement age.
The beauty of Coast FIRE is flexibility. Many choose to transition to freelancing, consulting, working for non-profits, tutoring, teaching, or taking entry-level roles in passions like gardening, coffee roasting, or library science. The only financial constraint is that the work must generate enough income to cover your monthly utilities, rent/mortgage, food, and basic necessities.