Explore whether the retirement investments you’ve already built may be enough to grow into financial independence by your planned retirement age.
CoastFI is the point where your current retirement investments may already be able to grow into your retirement goal without additional retirement contributions. It doesn’t mean you can retire today. It means time and compounding may already be doing more of the work for your future.
This calculator is a beta version! We have tested the numbers on this calculator extensively, but Murphy’s law rules the internet. We would love feedback, including any errors you may find.
If you’d like to run more extensive simulations, control more variables and have more inputs, check out these resources.
CoastFI Calculator beta
Start with a quick estimate using just four numbers. If you’re curious, keep going to explore how continued investing and different planning assumptions could change the picture.
Planning assumptions are not predictions.
This calculator is for education and exploration only. Women’s Personal Finance does not provide legal, tax, investment, or individualized financial advice. Use this as a starting point for understanding trade-offs, not as a guarantee or professional recommendation.
This tool uses simplified real-return math and does not model taxes, account types, asset allocation, market volatility, or sequence-of-returns risk.
Am I CoastFI?
Most people only need this section. Enter four numbers for a quick estimate using the default assumptions below.
A net worth tracker can help you see retirement accounts, brokerage accounts, and other investments in one place.
Track your investments with our favorite free tool → Affiliate disclosure: WPF may earn a commission if you sign up through this link.When could this happen?
This section estimates when you may reach CoastFI and FI based on your current investments, age, spending, and the annual contribution amount below. Projected CoastFI age is the first age where you could stop making retirement contributions and still be on track to reach your FI goal by your planned retirement age. Because there is less time for compounding each year, the CoastFI target increases as you get closer to retirement.
CoastFI Age is when retirement contributions may become optional if your goal is to retire at your planned retirement age. Full FI Age estimates when your portfolio could reach your full Financial Independence target if you continue contributing the annual amount entered above.
Explore different futures
Every calculator makes assumptions. These planning scenarios let you see how much the answer changes.
What changes if you reach CoastFI?
Reaching CoastFI doesn’t tell you what to do next. It simply gives you another way to think about your options.
If your retirement investments may already be on track to reach your retirement goal, continuing to build retirement savings may no longer need to compete with every financial decision you make today.
Some people keep investing because they want a larger cushion or the option to retire earlier. Others reduce their hours, change careers, travel more, spend more time with family, support causes they care about, or simply enjoy the peace of mind that comes from knowing they’re on track.
There isn’t one right answer. CoastFI is a planning milestone, not a rule for what you should do next.
Want to talk through the trade-offs?
WPF Insiders is where members compare assumptions, discuss real-life money decisions, and think through what the numbers could mean for their actual lives. CoastFI isn’t about finding one perfect answer; it’s about deciding what matters most to you.
Learn more about WPF InsidersPlay with the numbers
Want to model higher inflation, lower returns, or a different withdrawal rate? Change the assumptions directly.
8% return and 3% inflation equals about 4.9% real return.
Frequently asked questions
Why is it called CoastFI?
CoastFI gets its name from the idea that you may be able to “coast” to Financial Independence. Under the assumptions you choose, your existing retirement investments may already be doing enough work that you would not need to keep contributing to retirement savings to reach your retirement goal.
What changes if I reach CoastFI?
CoastFI can change how you think about future retirement contributions, current income needs, and flexibility. The section above gives examples of how people might use that milestone differently.
Why does my CoastFI number get closer to my FI number as I get older?
CoastFI assumes your investments have time to grow before retirement. As you get closer to your planned retirement age, there are fewer years left for compounding. At your planned retirement age, your CoastFI target and FI target become the same number.
Why doesn’t my FI number increase with inflation?
This calculator works in today’s dollars and uses real return, which means investment growth after inflation. This keeps your spending target and FI number in today’s purchasing power instead of showing larger future-dollar amounts.
Do I have to reach CoastFI or Financial Independence to retire?
No. CoastFI and Financial Independence are planning milestones, not requirements for retirement. Many people retire using some combination of savings, Social Security, pensions, changing spending, part-time work, home equity, or other income sources.
Should I adjust for taxes or account types?
Yes, if you want a more precise estimate. This calculator treats retirement investments as one combined number. In real life, Roth accounts, traditional pre-tax accounts, taxable brokerage accounts, HSAs, pensions, and other assets can have different tax treatment and spending flexibility.
Should my expected return match my investments?
Ideally, yes. Choose assumptions that roughly match your investment mix, risk tolerance, and time horizon. A stock-heavy portfolio, bond-heavy portfolio, and cash-heavy portfolio should not use the same long-term return assumption.
How are annual contributions treated?
Annual contribution estimates assume the money is invested and compounded annually. The calculator does not model exact contribution timing, paycheck-by-paycheck investing, taxes, fees, or market volatility.
Math behind this tool
1. Full FI number
2. CoastFI number today
3. Real return
4. Progress
All dollar amounts are shown in today’s purchasing power unless otherwise noted.