🏖️ Coast FIRE Calculator

Find out if your investments can grow to financial independence on their own

Amounts are shown in dollars ($), but the math works the same in any currency — euros, pounds, or anything else. Just enter your numbers.

years
years
Coast FIRE depends on how many years of compound growth remain. A longer runway means a lower Coast FIRE Number.
$
%
Average real return: Default is 7% (already adjusted for inflation). A diversified stock-heavy portfolio has historically returned ~10% nominal minus ~3% inflation ≈ 7% real. Adjust based on your risk tolerance and test multiple scenarios.
$
Enter your expenses in today's money. The default 7% return already accounts for inflation, so your FIRE number stays in today's dollars — the number you can actually relate to.

Your Coast FIRE Results

Coast FIRE Number
--
The amount you need invested today to stop contributing
Your Current Investments
--
What you have invested right now
FIRE Number at Retirement
--
25× annual expenses (4% rule)
Projected Portfolio at Retirement
--
Your investments at retirement, with zero further contributions

📊 Progress to Coast FIRE

$0

📅 Coast FIRE at Different Retirement Ages

Same investments, same expenses, same return — only the retirement age changes. Notice how a few extra years dramatically lowers the bar.

Retire At Years Left Coast Number Status

⚡ What If I Keep Contributing?

Coast FIRE means you can stop investing. But what happens if you don't?

$

💡 Your Inputs at a Glance

Current Age --
Target Retirement Age --
Years of Compounding --
Current Invested Assets --
Average Real Return --
Monthly Expenses (Retirement) --

📊 How We Calculate Your Coast FIRE Number

1. What Is Coast FIRE?

Coast FIRE is the point where your existing investments, left completely alone, will grow to your full FIRE number by your target retirement age through compound growth — without another dollar contributed.

Once you reach Coast FIRE, your only financial obligation is covering your current living expenses. You no longer need to save aggressively, which opens up options: work part-time, switch to a lower-paying job you enjoy, take a career break, or simply reduce your working hours.

2. The FIRE Number (Your Finish Line)

First, we calculate the portfolio you need at retirement using the 4% rule — 25 times your annual expenses.

FIRE Number = Monthly Expenses × 12 × 25

Example: $4,000/month → $48,000/year → $48,000 × 25 = $1,200,000

3. The Coast FIRE Number (Your Starting Line)

The Coast FIRE Number is the present value of your FIRE number — the amount that, if invested today, will grow to the FIRE number by your retirement age. We discount the FIRE number back to today using your expected real return and years remaining.

Coast FIRE Number = FIRE Number ÷ (1 + Real Return)Years to Retirement

Example: $1,200,000 ÷ (1.07)30 = $1,200,000 ÷ 7.612 = $157,614

If your current investments equal or exceed this number, you've reached Coast FIRE.

4. Why the Retirement Age Matters So Much

The sensitivity table above shows that even small changes to your target retirement age have an outsized impact on your Coast FIRE Number. That's the nature of compound growth: the longer money compounds, the less you need today. Moving your target from 55 to 60 can cut tens of thousands off the required amount, because those five extra years let compounding do significantly more work.

5. Why Inflation Is Already Handled

The default 7% return is a real return — it already accounts for inflation. Historically, a diversified stock portfolio has returned roughly 10% per year, minus about 3% inflation, giving ~7% real growth. Because the return is inflation-adjusted, all numbers in this calculator stay in today's dollars — the numbers you can actually relate to your current life.

If you want to be more conservative, simply lower the return rate (e.g., 5% or 6%) to stress-test your plan. This is more intuitive than adding a separate inflation variable.

6. What Coast FIRE Is Not

Coast FIRE is not full financial independence. You still need income to cover your day-to-day expenses until retirement — you've just removed the obligation to invest. It's also based on long-term averages. Markets don't return a steady 7% every year; actual growth is lumpy and unpredictable. A prolonged downturn early in your coasting period could delay the math. Treat this as a directional planning tool, not a guarantee.

Note: This calculator provides estimates based on historical averages and the 4% rule as a starting guideline. Real-world results vary based on market performance, actual inflation rates, tax situations, and life changes. Consider consulting with a financial advisor for personalized planning.