FIRE Number Calculator

Plan for different spending in each phase of retirement.


Spending Phases (in today's dollars)

Phase 1: Go-Go Years (active early retirement)

Phase 2: Slow-Go Years (moderate activity)

Phase 3: No-Go Years (lower activity + healthcare)

Your FIRE Number

$0

portfolio needed at FIRE age

Simple FIRE Number (for comparison)

$0

25x highest annual spending

Projected at FIRE Age

$0

Surplus / Shortfall

$0

Years to FIRE

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Portfolio Through Retirement

Spending Phase Summary

Why Variable Spending Matters

Most FIRE calculators assume flat spending throughout retirement. In reality, spending follows a "smile curve": higher in early retirement (travel, hobbies), lower in middle years, then potentially higher again due to healthcare costs.

The Three Retirement Phases

  • Go-Go Years (early): Active lifestyle, travel, dining — typically the highest spending phase
  • Slow-Go Years (middle): Less travel, more routine — spending naturally decreases 20-30%
  • No-Go Years (late): Less activity but potentially higher healthcare costs — spending varies widely

How This Calculator Differs

Instead of using a single "annual spending" number multiplied by 25, this calculator models the actual cash flows needed in each phase of retirement, discounting them back to your FIRE date to find the true portfolio size required. This often results in a lower FIRE number than the simple 25x rule.