Select Your Age
Your Coast FIRE Number
Advanced Parameters
Age Group Comparison
| Age | Coast FIRE Number | Years to Retirement | Monthly Savings Needed |
|---|---|---|---|
| 25 | $66,780 | 40 years | $139 |
| 30 | $93,663 | 35 years | $223 |
| 35 | $131,367 | 30 years | $365 |
| 40 | $184,249 | 25 years | $614 |
| 45 | $258,419 | 20 years | $1,077 |
| 50 | $362,446 | 15 years | $2,014 |
| 55 | $508,349 | 10 years | $4,236 |
| 60 | $712,986 | 5 years | $11,883 |
Coast FIRE Number Trend by Age
The red dot indicates your current age. Notice how the required Coast FIRE number increases exponentially with age due to less time for compound growth.
Understanding Your Coast FIRE Number
What Your Number Means
Your Coast FIRE number represents the savings milestone where you can stop making retirement contributions and let compound interest do the rest. Once you hit this number, you've secured your retirement—even if you never save another dollar. This gives you incredible financial flexibility to pursue lower-paying passions, work part-time, or take career risks.
Why Numbers Increase with Age
Coast FIRE numbers grow exponentially with age because you have less time for compound growth. A 25-year-old needs only $93,663 for a $1 million retirement goal, while a 55-year-old needs $505,068—over 5 times more. This exponential curve demonstrates the massive advantage of starting your Coast FIRE journey early in your career.
Comparing to Your Current Savings
Compare your actual savings to your Coast FIRE number to assess your progress. If you're ahead, congratulations—you're on track to coast! If you're behind, calculate the monthly savings needed to catch up. Remember, these are benchmarks based on standard assumptions; your personal situation may require adjustments.
Creating Your Action Plan
Use your Coast FIRE number as a concrete savings target. Divide it by the number of months until your target age to calculate required monthly savings. For example, if you're 25 and need $93,663 by 30, that's $1,561 per month for 5 years. Adjust your budget, increase income, or optimize investments to hit this goal.
What is Coast FIRE Number by Age?
Coast FIRE Number Examples by Age
See real-world examples of Coast FIRE numbers for different age groups and spending levels.
Example 1: 30-Year-Old Early Career Professional
Sarah is a 30-year-old software engineer living in Austin, Texas. She earns $85,000 annually and has been diligently saving since graduating college. Single and renting a one-bedroom apartment, she expects to spend $40,000 per year in retirement starting at age 65. She has 35 years for her investments to grow.
Calculation Steps
- Current Age: 30 years old
- Retirement Age: 65 years old (35 years to grow)
- Annual Retirement Spending: $40,000
- Investment Return: 7% annually
- Withdrawal Rate: 4% (safe withdrawal rule)
- Retirement Corpus Needed: $40,000 ÷ 0.04 = $1,000,000
- Coast FIRE Number: $1,000,000 ÷ (1.07)^35 = $118,745
Example 2: 40-Year-Old Mid-Career Professional
Michael is a 40-year-old marketing manager in Chicago with a wife and two young children. He earns $110,000 annually but started saving for retirement later due to student loans and family expenses. He has the same retirement goals as Sarah but only 25 years for compound growth.
Calculation Steps
- Current Age: 40 years old
- Retirement Age: 65 years old (25 years to grow)
- Annual Retirement Spending: $40,000
- Investment Return: 7% annually
- Withdrawal Rate: 4% (safe withdrawal rule)
- Retirement Corpus Needed: $40,000 ÷ 0.04 = $1,000,000
- Coast FIRE Number: $1,000,000 ÷ (1.07)^25 = $184,249
Example 3: 50-Year-Old High-Income Earner
Jennifer is a 50-year-old corporate attorney in New York City earning $180,000 annually. Divorced with grown children, she owns her condo and plans to spend $60,000 per year in retirement, reflecting a comfortable lifestyle with travel and hobbies.
Calculation Steps
- Current Age: 50 years old
- Retirement Age: 65 years old (15 years to grow)
- Annual Retirement Spending: $60,000 (higher lifestyle)
- Investment Return: 7% annually
- Withdrawal Rate: 4% (safe withdrawal rule)
- Retirement Corpus Needed: $60,000 ÷ 0.04 = $1,500,000
- Coast FIRE Number: $1,500,000 ÷ (1.07)^15 = $543,934
How to Use the Coast FIRE by Age Calculator
Follow these simple steps to find your Coast FIRE number and understand your retirement savings target.
Select Your Current Age
Use the age slider or input box to select your current age between 18 and 70 years old. The calculator will instantly show you the Coast FIRE number for your age group based on standard retirement assumptions.
Review Your Coast FIRE Number
See the exact dollar amount you need to have saved today to coast into retirement. This number is calculated using the 4% withdrawal rule (Trinity Study, 1998) and assumes a 7% annual investment return with retirement at age 65.
Compare Across Age Groups
Examine the age comparison table and trend chart to see how Coast FIRE numbers change with age. Notice how the required savings increase exponentially as you get older due to less time for compound growth.
Adjust Parameters (Optional)
Customize your calculation by adjusting retirement age, annual retirement spending, investment return rate, and withdrawal rate to match your personal situation and risk tolerance. Watch how these changes affect your Coast FIRE number in real-time.
Understanding the Parameters
Learn what each parameter means and how it affects your Coast FIRE number calculation.
Current Age
Your age today, ranging from 18 to 70 years old. This is the most critical factor because it determines how many years your money has to grow through compound interest before retirement. Younger ages result in dramatically lower Coast FIRE numbers.
Retirement Age
The age at which you plan to retire and begin withdrawing from your savings. Traditional retirement age is 65, but you can adjust this based on your personal goals. Earlier retirement requires a higher Coast FIRE number today.
Annual Retirement Spending
How much money you expect to spend each year during retirement, covering all living expenses including housing, food, healthcare, and leisure. This determines the total retirement corpus you'll need to accumulate by retirement age.
Investment Return Rate
The expected annual return on your investments before retirement. The default 7% represents a conservative estimate based on historical stock market returns. Higher returns mean you need less saved today, but be realistic about market volatility.
Withdrawal Rate
The percentage of your retirement corpus you can safely withdraw each year without running out of money. The 4% rule is widely accepted as sustainable, based on historical market data and the Trinity Study research.
Inflation Rate (Optional)
The expected annual inflation rate that will increase your future expenses. While not included in the default calculation, you can enable inflation adjustment to see how rising costs affect your required savings target over time.
The Coast FIRE Calculation Formula
Understanding the math behind your Coast FIRE number helps you make informed decisions about your savings strategy.
Retirement Corpus Calculation
First, we calculate the total amount you need saved by retirement age using the safe withdrawal rate principle. If you plan to spend $40,000 per year and use a 4% withdrawal rate, you need $1,000,000 saved ($40,000 ÷ 0.04 = $1,000,000). This ensures your money lasts throughout retirement.
Retirement Corpus = Annual Retirement Spending ÷ (Withdrawal Rate ÷ 100)
Example: For $40,000 annual spending with 4% withdrawal rate: $40,000 ÷ 0.04 = $1,000,000 retirement corpus
Coast FIRE Number Calculation
Next, we discount the retirement corpus back to present value using compound interest. This tells you how much you need saved today so it grows to your retirement corpus by retirement age. The longer the time horizon, the less you need today due to compound growth.
Coast FIRE Number = Retirement Corpus ÷ (1 + Investment Return Rate)^Years Until Retirement
Example: For $1,000,000 corpus, 7% return, 35 years: $1,000,000 ÷ (1.07)^35 = $118,745 Coast FIRE number at age 30
Inflation Adjustment (Optional)
Optionally, you can adjust for inflation by projecting your future retirement spending in today's dollars. With 3% annual inflation over 35 years, $40,000 today becomes $112,655 in purchasing power. This increases your required Coast FIRE number but provides a more realistic target.
Adjusted Spending = Annual Spending × (1 + Inflation Rate)^Years Until Retirement
Example: For $40,000 spending, 3% inflation, 35 years: $40,000 × (1.03)^35 = $112,655 future spending value
Frequently Asked Questions
Get answers to common questions about Coast FIRE numbers by age.
The Coast FIRE number by age is the amount you need saved at your current age so that your investments can grow to your full retirement needs without additional contributions. It varies dramatically by age—younger people need much less because their money has more time to compound. For example, a 30-year-old needs about $119,000 to reach $1 million by 65, while a 50-year-old needs $363,000 for the same goal.
Coast FIRE numbers increase exponentially with age due to compound interest working in reverse. Each year you wait means one less year for your money to double and grow. The difference between starting at 25 versus 35 is massive—you need roughly twice as much saved at 35 to reach the same retirement goal. This exponential curve is why financial advisors emphasize starting retirement savings as early as possible.
These benchmarks are mathematically accurate based on the assumptions used (7% return, 4% withdrawal rate, $40,000 annual spending, retirement at 65). However, your personal situation may differ significantly. Market returns vary, inflation affects purchasing power, and your spending needs are unique. Use these numbers as starting points and adjust the parameters to match your specific circumstances and risk tolerance.
Always use your current age to find your Coast FIRE number. This tells you how much you need saved right now to coast into retirement. Your target Coast FIRE age is simply when you plan to hit this number—it could be your current age if you're already there, or a future age you're working toward. The calculator shows you the savings target for today based on your current age.
Being behind your age group's benchmark is common and not a reason to panic. First, verify the assumptions match your situation—you may need less if you plan lower retirement spending or have pension income. Second, calculate how much you need to save monthly to catch up by your target age. Third, consider working a few years longer, which dramatically reduces your required Coast FIRE number. Many people reach Coast FIRE in their 40s or 50s and still achieve financial independence.
Yes! Click the 'Advanced Parameters' button to customize retirement age, annual spending, investment return rate, and withdrawal rate. Adjusting these dramatically changes your Coast FIRE number. For example, planning to retire at 70 instead of 65 cuts your required savings nearly in half. Similarly, reducing retirement spending from $40,000 to $30,000 lowers your target by 25%. Experiment with different scenarios to find your optimal path.