Coast FIRE Calculator

Find the portfolio amount you need today so compounding can carry you to retirement without adding new contributions.

Quick answer

Coast FIRE means you have enough invested now that future growth alone can hit your retirement target. Most people calculate the retirement target using a conservative withdrawal rate (often 3.5% for long retirements), then discount it back to today using expected real returns.

Inputs

Current age

Retirement age

Annual retirement spending

Withdrawal rate (%)

Expected real return (%)

Current invested portfolio

Coast FIRE target today

$506K

For age 35 to 60 (25 years)

Retirement target$1.71M

Current portfolio$250K

Gap to coast$256K

You need about $256K more invested to Coast FIRE.

Coast FIRE depends heavily on return assumptions. Use conservative real returns and a lower withdrawal rate (often 3.5% for long retirements), then verify outcomes with Monte Carlo and historical stress tests in RetireNumber.

Related calculators: 4% Rule, Barista FIRE, Retirement Number, All calculators.