Coastal FIRE Calculator

Coastal FIRE is the point at which your current retirement savings, left untouched to grow through compound investment returns alone, will reach your full retirement number by the time you reach traditional retirement age. Once you hit that point, you no longer need to keep adding new savings toward retirement, only cover your everyday living costs from work, which is why people describe it as being able to coast the rest of the way.

Traditional FIRE targets a lump sum large enough to fully fund early retirement through withdrawals alone, often requiring aggressive saving well into your thirties or forties. Coastal FIRE has a lower bar, it only asks whether your current balance will passively grow into your retirement number by a normal retirement age, which makes it reachable much earlier for many savers, even without cutting spending sharply.

4 percent is the most commonly referenced starting point, based on historical research into how large a withdrawal a retirement portfolio can typically sustain over a multi-decade retirement. Some planners use a more conservative 3 to 3.5 percent for extra safety margin, or a slightly higher rate for a shorter expected retirement, so treat 4 percent as a reasonable default rather than a fixed rule.

A commonly used range for a diversified stock and bond portfolio is 6 to 8 percent per year before adjusting for inflation, or roughly 4 to 6 percent if you want a more conservative, inflation-adjusted figure. This calculator does not know your specific asset allocation, so consider running the numbers twice, once with an optimistic rate and once with a more cautious one, to see how sensitive your result is.

Only indirectly, through whichever return rate and expense figure you choose to enter. If you enter your annual expenses in today's dollars and use an inflation-adjusted, or real, return rate, the result approximates what your Coast FIRE number would look like in today's purchasing power. If you prefer to work in nominal terms, use a higher, non-adjusted return rate and expect the dollar figures to represent future, inflated dollars instead.

That is the normal starting point for most people, not a bad result. Switch to the second calculator mode and enter a realistic monthly contribution to see approximately how many years of continued saving it would take before your trajectory crosses the coast threshold, after which additional saving becomes optional rather than necessary.

Yes. The retirement age field is fully adjustable, and it directly changes how many years your current balance has left to compound, which is the single biggest factor in your Coast FIRE number. A later planned retirement age lowers the amount you need today, since your money has more time to grow, while an earlier target raises it.

No. This calculator is an educational estimate based on the numbers and assumptions you enter, not personalized financial, investment, or retirement advice. Actual investment returns vary and are never guaranteed, and a qualified financial advisor can help you account for your full financial picture, including taxes, healthcare costs, and risk tolerance.