Coast FIRE Calculator
Find the savings that will coast to retirement.
Real or nominal, be consistent
Results update as you type.
How it works
Coast FIRE is a milestone on the path to financial independence: the point at which you have enough invested that, even if you never contribute another dollar, compound growth alone will carry your portfolio to your full retirement target by the time you retire. This calculator finds that number. You enter your retirement target, often your FIRE number, the years until you retire, and your expected annual return, and it returns your Coast FIRE number, the amount you need invested today. The calculation discounts the future target back to the present using the expected return over the time remaining, since money invested now compounds over those years. Reaching Coast FIRE is liberating because once you hit it, you no longer need to save for retirement at all; you only need to cover your current living expenses, freeing you to work less, switch to a lower-paying but more fulfilling job, or stop retirement contributions. It arrives much earlier than full FIRE, especially for younger people with decades of compounding ahead, because time does the heavy lifting. Be consistent with your return assumption: if you use a real, inflation-adjusted return, express your target in today's dollars too. The result depends heavily on the return and years assumed, so treat it as an estimate. Enter your target, years to retirement, and expected return to compute your Coast FIRE number.
Coast FIRE = target / (1 + return)^years
The Coast FIRE number is your retirement target discounted back to today by the expected annual return over the years until retirement. It is the amount you need invested now so that, with no further contributions, compounding alone grows it to your full retirement target by the time you retire.
Source:Financial independence planning
We review all our tools from time to time to ensure accuracy.
Worked example
How to use this calculator
- 1
Enter your values
Enter retirement target (fire number), years to retirement and expected annual return.
- 2
Adjust the options
Fine-tune any options to match your situation.
- 3
Read your result
Coast FIRE number updates instantly as you type — no button to press.
Frequently asked questions
What is Coast FIRE?
Coast FIRE is the point where you have enough invested that compound growth alone, with no further contributions, will reach your retirement target by the time you retire. After hitting it, you only need to cover current expenses, not save for retirement, giving you flexibility to work less or change careers.
How is the Coast FIRE number calculated?
Discount your retirement target back to today using your expected annual return over the years until retirement. The Coast FIRE number is the target divided by one plus the return, raised to the number of years. The calculator does this, giving the amount you need invested now to coast to your goal.
How is Coast FIRE different from regular FIRE?
Regular FIRE is the full portfolio needed to retire and live off withdrawals. Coast FIRE is a smaller, earlier milestone: enough invested that it will grow into the full FIRE number on its own by retirement, without more contributions. You reach Coast FIRE well before full FIRE, especially when retirement is many years away.
What can I do after reaching Coast FIRE?
Once you hit Coast FIRE, you no longer need to save for retirement, since your existing investments will grow to your target. You still need income to cover current living expenses, but you can stop retirement contributions, reduce your hours, take a lower-paying but more enjoyable job, or take career risks with less financial pressure.
Why does the return assumption matter so much?
The Coast FIRE number depends heavily on the expected return and the years until retirement, because compounding over decades is powerful and sensitive to the rate. A higher assumed return or more years lowers the amount needed today. Be realistic and consistent, using a real return with a today's-dollar target, and treat the result as an estimate.