Coast FIRE Calculator
Calculate how much you need saved today so your investments can grow to fully fund retirement later.
Plan your Coast FIRE number in seconds. Enter your current savings, expected growth, and retirement age to see when your portfolio can carry you to financial independence, even if you reduce future contributions.
Coast FIRE Projection
Your money’s growth path without further contributions.
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What Is Coast FIRE?
Coast FIRE is a strategy where you invest enough early that your portfolio can grow on its own to reach your traditional FIRE number by retirement age, even if you reduce or stop new contributions later.
In plain English:
You sprint early, then you coast.
Coast FIRE is different from traditional FIRE because your goal is not to retire immediately.
Your goal is to reach a point where retirement becomes inevitable if you simply maintain your portfolio and give it time.
Coast FIRE Concept
When your portfolio earns more than you do.
Once you reach this milestone, you stop contributing. Your paycheck is now liberated to cover:
Coast FIRE vs Traditional FIRE
Traditional FIRE usually means you keep saving aggressively until your portfolio can cover expenses right away.
Coast FIRE means you build the foundation early, then let time do most of the work.
Quick Comparison Table
| Strategy | Goal | What happens after you hit the milestone? |
|---|---|---|
| Traditional FIRE | Retire early soon | Work becomes optional now |
| Coast FIRE | Retirement is funded by growth | You can reduce saving pressure and “coast” |
| Barista FIRE | Semi-retire with part-time income | You use some portfolio + some income |
What Is the Coast FIRE Number?
Your Coast FIRE number is the amount that, if invested today, can grow to your retirement goal by your retirement age with no additional contributions required.
It depends on:
- Your retirement spending goal
- Your retirement age
- Inflation assumptions
- Expected investment returns
- Your withdrawal rate (often modeled around 4%)
Coast FIRE Formula
Calculate Your Retirement FIRE Number
The 25× rule provides the baseline for sustainable independence.
Multiplying by 25 is the mathematical inverse of withdrawing 4% per year. Both aim to ensure your portfolio outlives you.
Determine Your Starting Point
This formula reverse-engineers your goal using compound growth.
Note: By using a “Real Return” (subtracting inflation from your growth estimate), the resulting number stays in today’s purchasing power. This makes your target much easier to track against your current net worth.
Example Coast FIRE Calculation
Let’s say:
- retirement spending goal: $50,000/year
- retirement FIRE number (25×): $1,250,000
- years until retirement: 25
- expected annual return: 7%
Coast FIRE Number = 1,250,000 ÷ (1.07)^25 ≈ $230,000
If you already have $200,000 invested, you’re close.
You may only need roughly $30,000 more to hit Coast FIRE (depending on assumptions).
How the Coast FIRE Calculator Works
The calculator estimates two key outcomes:
- Your Coast FIRE number (today’s target)
- Your projected retirement portfolio value at your retirement age
It does this by combining:
- current invested balance
- optional ongoing contributions
- growth rate assumptions
- retirement age target
- retirement spending goal and withdrawal rule
The result is a forward-looking projection that shows whether you’re “on track to coast.”
Key Benefits of Coast FIRE
Reduced Pressure to Save Forever
Once your Coast FIRE number is hit, you may not need aggressive retirement contributions for life.
Career Flexibility
Many people use Coast FIRE to:
- switch to lower-stress work
- start a business
- take breaks
- work part-time
Lifestyle Balance
Coast FIRE supports a “live now and still retire well” approach, without waiting decades to enjoy your time.
The Real Risks of Coast FIRE (Read This)
Coast FIRE is powerful, but not magic. Risks include:
Navigating the Variables
Coast FIRE is powerful, but not magic. Understanding these risks is essential for a resilient plan.
Returns aren’t guaranteed, and bad decades can happen. Growth is not smooth.
If inflation runs hotter than expected, your future spending target rises.
A market downturn close to retirement can delay full independence.
If your lifestyle costs rise later, the retirement target increases, and your Coast plan may fall short.
Best Assets for Coast FIRE
Coast FIRE works best with assets that can compound over decades with low friction.
Common Coast FIRE-friendly assets
- diversified stock index funds
- low-cost ETFs
- balanced funds (for those closer to retirement)
- real estate (when managed prudently)
Coast FIRE can work without stocks, but it usually becomes harder because long-term compounding is the engine of the strategy.
Do You Still Need to Invest After Hitting Coast FIRE?
Not necessarily for retirement, but many people still invest for:
- Extra safety margin
- Earlier retirement age
- Higher lifestyle spending in retirement
- Insurance against market underperformance
Think of Coast FIRE as a floor, not a ceiling.
Coast FIRE for Average Earners
Yes, Coast FIRE can be realistic for average earners because it focuses on:
- Starting earlier
- Consistent investing
- Avoiding lifestyle inflation
Coast FIRE is often easier than traditional FIRE because the goal is not to quit working tomorrow. It’s to remove the long-term retirement burden as early as possible.
Coast FIRE With a Family
Coast FIRE can work with a family, but you must model:
- Childcare and schooling costs
- Housing stability
- Healthcare and insurance needs
- Emergency buffers
Families often use Coast FIRE as a flexibility strategy rather than a strict “stop saving forever” plan.
Coast FIRE by Age
These are not rules, just practical milestones many people use. Earlier is easier because time is your biggest advantage.
| Target Age to Hit Coast FIRE | What it usually requires |
|---|---|
| 30 | very high early savings + early investing |
| 40 | consistent investing + stable expenses |
| 50 | solid savings base + conservative planning |
Coast FIRE and Taxes (What Changes)
Coast FIRE itself doesn’t change taxes, but your strategy can:
- reducing income can lower your tax bracket
- different account types (taxable vs retirement accounts) affect withdrawal planning
- capital gains and dividends can create tax drag in taxable accounts
Use the calculator for direction, then build your account strategy around your country’s tax rules and account types.
Frequently Asked Questions
Final Words
Coast FIRE is one of the smartest “middle paths” to financial independence.
You build the investment base early, then you buy flexibility later.
Use the Coast FIRE Calculator to find your Coast FIRE number, then treat it like a checkpoint you revisit each year as your life, income, and goals evolve.
Final Words
Coast FIRE is one of the smartest “middle paths” to financial independence.
You build the investment base early, then you buy flexibility later.
Use the Coast FIRE Calculator to find your Coast FIRE number, then treat it like a checkpoint you revisit each year as your life, income, and goals evolve.