Coast FIRE Calculator

What Is Coast FIRE?

Coast FIRE is the point where you've invested enough that, even if you never contribute another dollar, compound growth alone will carry your portfolio to your full financial independence number by the time you reach retirement age. Once you're there, you can "coast" — working purely by choice, taking a lower-paying but more enjoyable job, or covering just your current living costs — without derailing your long-term retirement plan.

It's a popular milestone in the FIRE (Financial Independence, Retire Early) community because it separates two different goals: growing your net worth and covering today's expenses. Once you've hit Coast FIRE, only the second one still requires active income.

How to Use This Calculator

Enter your current age, the age you're aiming to be financially independent by, what you've already got invested, and how much you expect to spend annually in retirement. The default 4% withdrawal rate and 7% expected return are common starting assumptions in FIRE planning, but you can adjust both to match your own outlook.

How We Calculate It

Your full financial independence (FI) number is your annual retirement spending divided by your withdrawal rate — for example, $40,000 in spending at a 4% withdrawal rate implies a $1,000,000 FI number. We then work out how much you'd need invested today for that amount to grow, at your expected return rate, into your FI number by your target retirement age. That's your Coast FIRE number.

If your current investments already exceed that number, you've reached Coast FIRE. If not, the calculator also estimates the age at which your current savings alone — with no further contributions — would reach your FI number at your expected return rate, so you can see roughly how far off you are.

A Few Notes

This calculator assumes a steady, constant rate of return, which real markets never actually deliver year to year — treat the result as a long-term planning estimate, not a guarantee. If you use an expected return that's already adjusted for inflation (a common approach), your spending figure should also be in today's dollars, and the result will be too. This tool is for general planning purposes only and isn't personalized financial advice.