Coast FIRE Calculator
Estimate your Coast FIRE number and see when you could stop contributing while your investments grow toward your retirement goal.
- 100% Free
- No Sign Up
- Private Inputs
How it works
How to Use the Coast FIRE Calculator
Enter your details, choose your assumptions, then compare your retirement scenario.
01
Add your starting point
Enter your age, invested assets, monthly contribution, and retirement spending.
02
Set realistic assumptions
Adjust return, inflation, and withdrawal rate for the scenario you want to explore.
03
Compare the projection
See your Coast FIRE number, projected milestone age, and retirement target.
The Coast FIRE idea
What Is Coast FIRE?
It is the point where your investments may grow to your retirement target without new retirement contributions.
- 01
Invest today
Current assets
- 02
Keep working
Time and growth
- 03
Reach your target
Retirement income
The estimate is a planning view, not a guarantee or a recommendation to stop saving.
Formula
How the Coast FIRE Formula Works
First estimate the retirement target. Then calculate how much needs to be invested today.
Retirement portfolio target
Annual retirement spending / Safe withdrawal rate
Coast FIRE number
Retirement portfolio target / (1 + real annual return)^years to retirement
Real annual return = expected annual return - inflation rate.
Understanding your result
Understanding Your Results
Use these three signals to understand and compare retirement scenarios.
Coast FIRE number
The investment balance estimated to grow to your retirement target without further contributions.
Projected milestone
The first yearly age where your continued contributions meet the Coast FIRE number.
On track status
A signal that this scenario reaches the milestone before your chosen retirement age.
Key assumptions
Key Assumptions
Know what the calculator includes and what it leaves out before comparing scenarios.
- Today's dollars
- Spending, investments, and targets are presented in current purchasing power for a clearer comparison.
- Monthly contributions
- Contributions are modeled at the end of each month using the inflation-adjusted return assumption.
- Yearly checkpoints
- The calculator checks for Coast FIRE at complete yearly ages, matching the chart and result summary.
- What is excluded
- Taxes, fees, Social Security, pensions, debt, and market volatility are not included in this estimate.
FAQ
Coast FIRE Calculator FAQ
Clear answers about the calculator, the formula, and your result.
What is Coast FIRE?
Coast FIRE means you have invested enough that, under your assumptions, your portfolio may grow to your retirement target without additional retirement contributions. It does not mean you must stop working or saving.
What should I include in current invested assets?
Include investment accounts intended to support retirement, such as workplace retirement plans, IRAs, and taxable investment accounts. The calculator excludes home equity, emergency cash, and everyday checking balances by default.
How does the calculator account for inflation?
The calculator estimates an inflation-adjusted annual return by subtracting your inflation assumption from your expected annual return. Amounts are shown in today's dollars so you can compare spending and savings on the same basis.
What does on track mean?
On track means the projection reaches the Coast FIRE number at one of the yearly checkpoints before your chosen retirement age. It is an estimate based on the inputs you provide, not a guarantee of future investment performance.
Does the calculator save my financial information?
No. Your calculator inputs stay in your browser for this session and are not added to the URL, saved to local storage, or sent to a server by this tool.
Are the results guaranteed?
No. Investment returns, inflation, spending, taxes, fees, and life changes can differ from these assumptions. Use the result as an educational planning estimate and consider professional advice for important financial decisions.
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FireCalcTools is for educational and informational purposes only. Calculator results are estimates, not financial, investment, tax, or legal advice. Consider a qualified professional before making important financial decisions.