Coast FIRE Calculator

Find out if you already have enough saved to stop contributing and retire on time - letting compound growth do the heavy lifting.

$
$
Used to calculate your FI Target (25x)
%
7% is a common inflation-adjusted estimate
$
Used to calculate when you'll reach your coast number
USD - calculations use US conventions (4% rule, inflation-adjusted returns)
FI Target (25x)
-
Total needed to retire
Your Coast Number
-
Needed today to coast
Current Savings
-
What you have now
Gap to Coast
-
How much more needed
Disclaimer: These results are estimates for informational and educational purposes only. They do not constitute financial, investment, or tax advice. Assumed rates of return are not guaranteed. Full disclaimer ->
Downloads a PDF summary to your device

How to use this Coast FIRE calculator

Use this calculator when you want to know whether your current retirement savings could grow into your target retirement balance without additional contributions. The result is most useful when your spending estimate, retirement age, and return assumption are realistic.

Formula and assumptions

The calculator estimates a financial independence target as expected annual retirement spending multiplied by 25. It then discounts that future target back to today using the expected annual return and years until retirement. This simplified approach is based on the 4% rule and compound growth.

Example

If you expect to spend $60,000 per year in retirement, the simplified FI target is $1,500,000. A 35-year-old retiring at 65 has 30 years for savings to compound, so the amount needed today is far lower than the full target. Change the return assumption to see how sensitive the result is.

Common mistakes

  • Using an optimistic return without testing a conservative case.
  • Ignoring high-interest debt that competes with retirement contributions.
  • Using today's spending without thinking about healthcare, housing, taxes, or inflation.

How to interpret your result

If your current savings are above the coast number, the calculator is saying that your existing balance may be enough to reach the future target if left invested. It does not mean you can stop working or ignore future planning. If your savings are below the coast number, the gap shows how much more would be needed today under the selected assumptions.

What to test next

Run the calculator again with a lower return, a later retirement age, and a higher spending estimate. If the result still looks strong, the plan has more margin. If the result changes dramatically, the next step is to reduce debt, increase contributions, or lower future spending expectations.

For more context, read Coast FIRE by age and review the site's calculator methodology.

Frequently Asked Questions

What is Coast FIRE?
Coast FIRE is the point where you have saved enough in your retirement accounts that, even if you never contribute another dollar, compound growth alone will grow your savings to your FI number by your target retirement age. Once you hit your coast number, you only need to earn enough to cover current living expenses - not save for the future.
How is the Coast FIRE number calculated?
Your FI Target is 25 times your expected annual spending in retirement (the 4% safe withdrawal rule). Your Coast Number is then: FI Target / (1 + annual return)^years until retirement. For example, if you want $1.5M by age 65 and you're 35, with a 7% return, your coast number today is about $197,000.
What annual return rate should I use?
Most people use 7% as a conservative, inflation-adjusted estimate based on the historical average of a diversified US stock market index fund portfolio. You can lower this (5-6%) for a more conservative estimate, or raise it (8-10%) for an optimistic one. The default of 7% is a widely used benchmark.
What is the 4% rule?
The 4% rule is a retirement guideline stating you can safely withdraw 4% of your portfolio each year without running out of money over a 30-year retirement. This means you need 25 times your annual spending saved to be financially independent. It was derived from the Trinity Study and is a widely used starting point for retirement planning. High-interest debt is the most common reason people can't reach Coast FIRE - use our loan calculator to model a payoff plan first.

Related calculators

  • Subscription Bleed Calculator - cutting recurring costs accelerates your path to Coast FIRE by freeing up money to invest.
  • Loan Calculator - high-interest debt is what delays most people from coasting; model your payoff timeline here.