This Coast FIRE calculator helps you discover when you can stop contributing to retirement accounts and still reach your financial goals through compound interest alone. Whether you're feeling burned out from aggressive saving rates or wondering if you can finally pursue that career change, this tool shows you exactly how much you need to "coast" to a comfortable retirement.
Unlike traditional retirement planning that requires saving until you retire, Coast FIRE lets you front-load your savings early in your career, then redirect that money toward living more freely today. The result? You get financial security for the future while enjoying more flexibility right now.
What is Coast FIRE?
Coast FIRE (Financial Independence, Retire Early) means you've saved enough money that your current investments will grow to fully fund your retirement without any additional contributions. Think of it as hitting the savings finish line early - your money does the rest of the work through compound interest.
Here's a real example: Sarah, 32, has $150,000 saved for retirement. If she stops contributing now and her investments grow at 7% annually, she'll have about $1.2 million by age 65. Using the 4% withdrawal rule, that provides $48,000 in annual retirement income - enough for many people's retirement needs.
The beauty of Coast FIRE is psychological as much as mathematical. Once you hit your Coast number, the pressure to save aggressively lifts. You can take that lower-paying job you love, start a business, work part-time, or simply enjoy more of your income today knowing your retirement is already secured.
How Coast FIRE Works
The magic behind Coast FIRE is compound interest working over long time periods. When you invest money in your 20s and 30s, those dollars have decades to grow exponentially. Here's how the math breaks down:
The Coast FIRE Formula: Coast FIRE Number = Annual Retirement Spending ÷ (Safe Withdrawal Rate × (1 + Growth Rate)^Years to Retirement)
Real Example:
- Target retirement spending: $60,000 annually
- Safe withdrawal rate: 4%
- Investment growth rate: 7%
- Years to retirement: 30
Coast FIRE Number = $60,000 ÷ (0.04 × 1.07^30) = $196,000
This means if you have $196,000 invested at age 35, you can stop contributing and still have enough for retirement at 65, even adjusting for inflation.
The key insight: starting early dramatically reduces how much you need. That same $60,000 retirement income only requires $89,000 saved if you're 25 years old, but jumps to $445,000 if you don't start until 45.
Coast FIRE vs Traditional FIRE
Coast FIRE offers a more sustainable middle ground between aggressive FIRE savings and traditional retirement planning:
| Approach | Savings Rate | Timeline | Lifestyle Impact |
|----------|--------------|----------|------------------|
| Traditional FIRE | 50-70% of income | Retire in 10-15 years | Extreme frugality required |
| Coast FIRE | High initially, then minimal | Work until traditional retirement | Front-loaded sacrifice, then freedom |
| Traditional Retirement | 10-15% consistently | Work until 65+ | Steady but limited lifestyle |
The Coast FIRE advantage becomes clear when you consider life changes. Maybe you want to have kids, care for aging parents, or pursue a passion project. Coast FIRE gives you the financial flexibility to make those choices without worrying about derailing your retirement.
Coast FIRE by Age: Real-World Benchmarks
Understanding Coast FIRE targets by age helps you gauge your progress. These examples assume retirement at 65 with $60,000 annual spending:
Age 25: Coast FIRE Target ~$89,000 Starting this early gives you incredible advantages. With 40 years of growth, even modest savings can reach Coast FIRE quickly.
Age 30: Coast FIRE Target ~$131,000 Still excellent timing. Many people have this much in their 401k after 8-10 years of consistent saving.
Age 35: Coast FIRE Target ~$196,000 This is achievable for disciplined savers who've maximized 401k contributions and received employer matches.
Age 40: Coast FIRE Target ~$297,000 Requires more aggressive saving, but still very doable for high earners or those who've received inheritance, bonuses, or investment gains.
Age 45: Coast FIRE Target ~$445,000 This level typically requires high income, significant employer contributions, or investment success. Still possible but requires commitment.
When You've Reached Coast FIRE: What's Next?
Congratulations! You've hit a major financial milestone. Now comes the fun part - deciding what to do with your newfound freedom. Here are realistic options people choose:
Reduce Work Stress: Many Coast FIRE achievers negotiate part-time schedules, switch to less demanding roles, or pursue careers they're passionate about rather than highest-paying options.
Accelerate Other Goals: Redirect retirement contributions toward paying off your mortgage, building wealth for your children's education, or creating an emergency fund that lets you sleep better at night.
Increase Lifestyle Spending: Finally take that European vacation, renovate your home, or enjoy dining out more frequently. You've earned the right to spend money on current happiness.
Build Extra Security: Some people continue modest retirement contributions for extra peace of mind or to enable earlier retirement than originally planned.
Start a Business: Coast FIRE provides the ultimate safety net for entrepreneurship. You can take calculated risks knowing your retirement remains secure regardless of business outcomes.
Coast FIRE for Couples
Couples face unique Coast FIRE opportunities and challenges. The key is coordinating different incomes, career trajectories, and risk tolerances.
Strategy 1: Combined Approach Pool your retirement accounts and calculate Coast FIRE based on household spending. This works well when both partners earn similar amounts and share financial goals.
Strategy 2: Staggered Approach One partner achieves Coast FIRE first and transitions to part-time work or a passion career, while the other continues building wealth. This is common when one person significantly out-earns the other.
Strategy 3: Individual Targets Each person maintains separate Coast FIRE goals. This provides maximum flexibility if life circumstances change, but requires higher overall savings.
Example: The Staggered Approach Mark (software engineer, $120k) and Lisa (teacher, $55k) have been married 8 years. Mark's aggressive 401k contributions and stock options helped him reach Coast FIRE at 34 with $180,000 saved. He negotiated a 4-day work week and took a 20% pay cut for better work-life balance. Lisa continues saving aggressively to reach her Coast FIRE number, knowing Mark's retirement is already secured.
Common Coast FIRE Mistakes to Avoid
Coast FIRE isn't foolproof. Here are realistic concerns and how to address them:
Mistake 1: Overestimating Investment Returns Using 10% expected returns instead of 7% can lead to dangerous shortfalls. Be conservative with assumptions, especially given recent market volatility.
Mistake 2: Underestimating Healthcare Costs Healthcare expenses often increase dramatically in later years. Consider building extra cushion into your Coast FIRE number if you have family health history concerns.
Mistake 3: Ignoring Inflation's Impact $60,000 today won't buy the same amount in 30 years. The calculator accounts for this, but many people psychologically struggle with the concept.
Mistake 4: Lifestyle Inflation After Coast FIRE Just because you can stop saving doesn't mean you should dramatically increase spending. Maintain reasonable lifestyle boundaries to preserve your achievement.
Mistake 5: Not Planning for Emergencies Coast FIRE assumes smooth sailing to retirement. Have robust emergency funds and insurance to avoid tapping retirement accounts early.
Investment Strategy for Coast FIRE
Your investment approach matters enormously for Coast FIRE success. Here's practical guidance:
Asset Allocation by Age:
- 20s-30s: 80-90% stocks, 10-20% bonds (growth focus)
- 40s: 70-80% stocks, 20-30% bonds (balanced growth)
- 50s+: 60-70% stocks, 30-40% bonds (moderate risk)
Focus on Low Costs: Investment fees compound negatively over decades. Index funds with expense ratios under 0.2% can save tens of thousands compared to actively managed funds charging 1%+.
Tax-Efficient Accounts: Maximize 401k contributions for immediate tax benefits, then contribute to Roth IRAs for tax-free retirement withdrawals. The order matters for optimizing your Coast FIRE timeline.
Stay the Course: Coast FIRE requires decades-long commitment. Market downturns will test your resolve, but historically, patient investors who ride out volatility achieve the returns that make Coast FIRE possible.
Practical Examples: Coast FIRE in Action
Example 1: The 28-Year-Old Teacher Emma teaches elementary school and earns $48,000 annually. She's saved $45,000 in her 403b and wants to retire at 60 with $50,000 annual spending. Her Coast FIRE target is $73,000, meaning she needs to save just $28,000 more. At her current savings rate of $400 monthly, she'll reach Coast FIRE in 6 years at age 34. Then she can stop retirement contributions and use that $400 monthly for travel, hobbies, or reducing work stress.
Example 2: The 35-Year-Old Tech Worker David works in tech earning $95,000 and has aggressively saved $180,000. His Coast FIRE target for retiring at 65 with $65,000 spending is $156,000 - he's already achieved it! David decides to continue working in tech for 2 more years while redirecting $1,200 monthly retirement contributions toward paying off his mortgage. Then he'll switch to a nonprofit job he's passionate about, earning 40% less but loving his work.
Example 3: The Dual-Income Couple Jennifer (nurse, $70k) and Mike (accountant, $85k) are 32 and 30 respectively. Together they've saved $220,000 and want to retire at 62 with $75,000 combined spending. Their Coast FIRE target is $185,000 - they've exceeded it! They decide Jennifer will go part-time after their second child is born, providing more family time while Mike continues his career. Their retirement is secure regardless of reduced household income.
Example 4: The Late Starter Patricia started focusing on retirement at 42 after paying off student loans and buying a house. She earns $78,000 and has saved $85,000. For retirement at 67 with $55,000 spending, she needs $145,000. She's $60,000 short, requiring about 4 more years of aggressive saving. While not ideal, Coast FIRE is still achievable with commitment.
Example 5: The Conservative Planner Robert uses conservative assumptions: 6% investment returns, 3.5% safe withdrawal rate, and higher retirement spending estimates. This increases his Coast FIRE target but provides extra security. His approach: better to exceed his goal than fall short due to overly optimistic planning.