Coast FIRE Calculator

What is Coast FIRE?

Coast FIRE is the point where your invested savings will grow to your full FIRE number by your target retirement age without any additional contributions. Once you reach Coast FIRE, you only need to earn enough to cover current expenses.

The Formula

Coast FIRE Number = FIRE Number ÷ (1 + return)^years

This uses the time value of money: a smaller amount today grows to a larger amount in the future thanks to compound growth.

Why Coast FIRE Matters

• Career flexibility: Take a lower-paying but fulfilling job
• Reduced stress: No pressure to maximize income
• Work optional: Work because you want to, not because you have to
• Geographic freedom: Move to lower cost-of-living areas
• Time freedom: Part-time work becomes viable

Types of FIRE

• Coast FIRE: Stop saving, cover expenses with work
• Barista FIRE: Semi-retirement with part-time work
• Lean FIRE: Early retirement with frugal lifestyle
• Fat FIRE: Early retirement with comfortable lifestyle
• Full FIRE: Complete financial independence

Important Considerations

• Returns are not guaranteed - market volatility affects the timeline
• Inflation erodes purchasing power over time
• Healthcare costs may require continued employment (in the US)
• Life circumstances change - expenses may increase
• Consider keeping an emergency fund separate from retirement savings

After Reaching Coast FIRE

Once you reach Coast FIRE, you have options but arent required to stop saving. Many people continue saving to accelerate retirement, build a buffer, or increase their target lifestyle. The point is having the freedom to choose.