Find out how much you need saved today to stop contributing and let compounding carry you to retirement.
Coast FIRE is a milestone within the FIRE (Financial Independence, Retire Early) movement. Instead of grinding until you hit your full FI number, you identify a point where your current savings — left alone — will grow to your full retirement number by the time you reach retirement age. Once you hit that Coast number, you can stop saving and let compounding do the rest.
The word "coast" is the key: you've climbed the hill, now you can coast downhill without pedaling. You still need income to cover living expenses, but that income doesn't need to go toward retirement anymore.
The FI Number is how much you need at retirement to safely withdraw 4% per year indefinitely (the "4% Rule" from the Trinity Study). The Coast number is simply the present value of that FI number — how much you need today so it grows into your FI number by retirement.
After hitting your Coast number, you can shift your entire income toward lifestyle rather than savings. You might work a lower-stress job, go part-time, pursue passion projects, or move to a lower cost-of-living area — anything that covers your current expenses without needing to save a dollar more. The market does the retirement saving for you.
The earlier you start, the lower your Coast number. A 25-year-old with 40 years of compounding needs far less saved than a 45-year-old with only 20 years to go. This is why Coast FIRE is particularly powerful for young savers who front-load their contributions and then pivot to more flexible work.
This calculator uses your nominal return for projections. The "Annual Expenses in Retirement" figure you enter should be in today's dollars — the 4% rule historically accounts for inflation over time, so you don't need to manually inflate the FI number.