FatFIRE Calculator

About this calculator

FatFIRE is a variant of the FIRE (Financial Independence, Retire Early) movement aimed at retiring early without cutting back — maintaining a comfortable, often upper-middle-class-or-higher lifestyle rather than the bare-bones budget associated with Lean FIRE. The target nest egg is calculated by dividing desired annual spending by a chosen withdrawal rate (commonly modeled around the 4% rule derived from the Trinity Study), so a higher target spending level and a more conservative withdrawal rate both push the required portfolio size up.

People pursuing FatFIRE typically have higher incomes, want to preserve travel, private schooling, a larger home, or other lifestyle spending in retirement, and often plan for a longer time horizon since 'early' can mean retiring decades before traditional retirement age — which increases sequence-of-returns risk and argues for a more conservative withdrawal assumption.

This calculator takes your desired annual spending and withdrawal rate and returns the portfolio size needed to sustain that lifestyle indefinitely.