🏖️ Coast FIRE means your investments are already on track — you can stop saving and just cover expenses. A 30-year-old with $250K invested at 7% hits $1.9M by 65 with zero additional contributions. Find your Coast FIRE number below. Why compound growth is your best friend →

Coast FIRE Calculator

Find out when your existing investments will grow to your FIRE number without any additional contributions.

Your Details

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Your Coast FIRE Number $0 What you need today
Your Full FIRE Number $0 At age 65
Age Year Portfolio Value ($0 contributions) Target Coast Milestone

Methodology

The Coast FIRE calculator projects your portfolio growth and retirement needs using the following mathematical formulas:

  • Years to Retirement: Target Retirement Age - Current Age
  • Future Annual Expenses: Annual Expenses × (1 + Inflation Rate)Years to Retirement
  • FIRE Number: Future Annual Expenses × 25 (This is based on the 4% safe withdrawal rate rule)
  • Coast FIRE Number: FIRE Number ÷ (1 + Nominal Return Rate)Years to Retirement

This calculator uses your expected nominal return rate and expected inflation rate to project future values. The Coast FIRE number tells you the exact amount you need invested today so that compounding interest alone will grow it to your full FIRE number by the time you retire.

Frequently Asked Questions

What is Coast FIRE?

Coast FIRE is the point at which your existing investments will grow to your target retirement number by your traditional retirement age without any additional contributions. Once you reach Coast FIRE, you no longer need to save for retirement.

How is the Coast FIRE number calculated?

Your Coast FIRE number is calculated by taking your full FIRE number (which is typically 25 times your annual expenses, adjusted for inflation over the years until retirement) and discounting it back to the present day using your expected real return rate.

What is a good real return rate to use?

Historically, the stock market has returned about 7-10% annually before inflation. A common conservative estimate for a real (inflation-adjusted) return rate is 5-7%.

Does Coast FIRE mean I can retire right now?

No, Coast FIRE means you can stop saving for retirement. You still need to cover your current living expenses until you reach your target retirement age. Many people choose to downshift to less stressful, lower-paying jobs once they reach Coast FIRE.

Why do I need to account for inflation?

Inflation reduces purchasing power over time. If your retirement is 20 years away, your annual expenses will be much higher in nominal terms than they are today. Adjusting for inflation ensures your FIRE number will actually cover your future lifestyle.