What is Coast FIRE?
Coast FIRE is a milestone in the Financial Independence journey where you have saved enough in your investment accounts that, given enough time and compound growth, your portfolio will reach your full FIRE number by traditional retirement age without any additional contributions. Once you hit Coast FIRE, you only need to earn enough to cover current living expenses -- you no longer need to save for retirement.
How Coast FIRE Is Calculated
The Coast FIRE number is derived from your full FIRE number (annual expenses divided by your safe withdrawal rate) discounted back to the present using your expected rate of return. The formula is: Coast FIRE Number = FIRE Number / (1 + return)^years. The longer your time horizon, the smaller your Coast FIRE number, because compound interest has more time to work.
Benefits of Coast FIRE
Reaching Coast FIRE unlocks significant lifestyle flexibility. You can switch to lower-paying but more fulfilling work, reduce hours, take extended breaks, or pursue entrepreneurial ventures. The psychological relief of knowing your retirement is secured -- regardless of future savings -- is substantial. Many people find Coast FIRE is a more realistic and motivating target than full FIRE.
Frequently Asked Questions
How does Coast FIRE differ from regular FIRE?â–¾
Regular FIRE means you have enough invested to cover all living expenses from investment returns immediately. Coast FIRE means you have enough saved that compound growth alone will get you to your FIRE number by a target retirement age. You still need income for current expenses, but you no longer need to save additional money for retirement.
What if the market underperforms my expected return?â–¾
Using a conservative return estimate (e.g., 5-6% instead of 7-10%) provides a safety margin. You can also continue making small contributions even after reaching Coast FIRE for extra protection. Sequence of returns risk matters less during accumulation than during withdrawal.
Does inflation affect my Coast FIRE number?â–¾
Yes. If you use a nominal return rate (e.g., 10%), your future expenses will also be higher due to inflation. For simplicity, many Coast FIRE calculators use a real (inflation-adjusted) return rate of around 5-7%, which automatically accounts for inflation. This calculator uses nominal returns, so consider using a lower rate like 5-6% if you want inflation-adjusted results.
At what age should I aim for Coast FIRE?â–¾
The younger you reach Coast FIRE, the more flexibility you have. Many people in their late 20s to mid 30s can reach Coast FIRE with aggressive saving early on. The key advantage of youth is that your Coast FIRE number is much lower because compound growth has decades to work. Someone at age 25 might need only $80,000 to coast to a $1M retirement by age 65.
Calclypso Editorial Team
Reviewed by certified financial planners. Last updated: April 2026. Coast FIRE calculations assume consistent annual returns and no additional contributions after reaching the Coast FIRE number.