COAST FIRE Calculator Guide

Master our COAST FIRE calculator with step-by-step instructions, examples, and pro tips for accurate results.

Quick Start Guide

Get your COAST FIRE number in under 5 minutes

1

Enter Basic Info

Input your current age, desired retirement age, and current savings

2

Set Assumptions

Choose your expected investment return and retirement spending needs

3

Get Results

Discover your COAST FIRE number and timeline to reach it

Calculator Input Fields Explained

Current Age

Your age today. This determines how many years of compound growth your investments will have until traditional retirement age.

Example: If you're 28 years old, enter "28"

Current Savings

Total amount currently invested in retirement accounts (401k, IRA, Roth IRA, taxable investment accounts). Don't include cash savings or emergency funds.

Include: 401k ($45,000) + IRA ($12,000) + Taxable Investments ($8,000) = $65,000
Exclude: Emergency fund, checking account, home equity

Desired Retirement Age

When you want to completely stop working and live off your investments. Most people choose between 60-67, but you can retire earlier or later.

Common choices: 62 (early Social Security), 65 (Medicare), 67 (full Social Security)

Annual Retirement Spending

How much money you'll need per year in retirement to maintain your desired lifestyle. Use today's dollars - inflation is handled separately.

Estimate methods:

  • • 70-80% of current annual expenses
  • • Current expenses minus mortgage, work costs, retirement savings
  • • Detailed retirement budget calculation

Expected Annual Return

Average annual investment return you expect after inflation. Historical stock market average is about 7% after inflation.

Conservative: 6% | Moderate: 7% | Aggressive: 8%
Recommendation: Use 6-7% for more conservative planning

Example Calculations

Example 1: Young Professional

Inputs:

  • Current Age: 25
  • Current Savings: $15,000
  • Retirement Age: 65
  • Annual Spending: $50,000
  • Expected Return: 7%

Results:

  • COAST FIRE Number: $186,000
  • Additional Needed: $171,000
  • Years to COAST FIRE: 8-10 years
  • Value at 65: $1.25M

Interpretation: If this person saves $171,000 by age 33-35, they can stop retirement savings and still have $1.25M at 65.

Example 2: Mid-Career Professional

Inputs:

  • Current Age: 35
  • Current Savings: $180,000
  • Retirement Age: 62
  • Annual Spending: $70,000
  • Expected Return: 6%

Results:

  • COAST FIRE Number: $485,000
  • Additional Needed: $305,000
  • Years to COAST FIRE: 7-9 years
  • Value at 62: $1.75M

Interpretation: Already well on their way! Needs to reach $485,000 by age 42-44 to achieve COAST FIRE.

Pro Tips for Accurate Results

Be Conservative

Use lower return assumptions (6% vs 8%) and higher spending estimates. It's better to exceed your goal than fall short.

Include All Accounts

Don't forget Roth IRAs, HSAs, taxable investment accounts, and any employer retirement contributions.

Plan for Inflation

The calculator uses real (inflation-adjusted) returns. Your spending estimate should be in today's purchasing power.

Update Regularly

Recalculate annually as your savings grow and life circumstances change. Your COAST FIRE timeline will improve over time.

Consider Healthcare

Factor in healthcare costs if retiring before Medicare eligibility. This can add $1,000-2,000 per month to your spending needs.

Test Scenarios

Try different retirement ages and spending levels to see how they impact your COAST FIRE number and timeline.

Calculator FAQ

What if I have a pension or Social Security?

Reduce your annual spending estimate by the amount these will cover. For example, if Social Security will provide $20,000/year, subtract that from your retirement spending needs.

Should I include my home value?

Generally no, unless you plan to sell and downsize in retirement. Your home provides shelter, not income. Focus on liquid investments.

What about taxes in retirement?

The spending amount should be your after-tax spending needs. If you have mostly traditional 401k/IRA funds, increase your spending estimate by 15-25% to account for taxes.

How accurate is the calculator?

The calculator provides estimates based on historical averages. Actual returns will vary year to year. Use it as a planning tool, not a guarantee.

Ready to Calculate Your COAST FIRE Number?

Use our calculator with confidence now that you understand how it works. Start planning your path to financial freedom today.