While some new additions to the FIRE family may fizzle out, FatFIRE, LeanFIRE, CoastFIRE, and BaristaFIRE have become common parlance in the community.
Each has permanently shifted how FIRE advocates approach their money, time, and life choices.
FatFIRE means spending a minimum of $100,000 each year of retired life, according to InspiretoFire. Following the 4% rule (a rule of thumb for retirees' annual withdrawal) would mean having a nest egg of at least $2.5 million.
Besides the apparent thrills of living large, FatFIRE offers a greater sense of security. Handling surprise medical expenses or other unforeseen emergencies is easier with deeper savings.
Frugality is essential for those on LeanFIRE, who typically try to get by on less than $40,000 per year.
Yet there are benefits to foregoing creature comforts. Since LeanFIRE followers live on tighter budgets, they can retire earlier with fewer overall savings. It allows them to fast-track their financial independence and have more time to enjoy the rest of their lives.
If someone invests enough upfront, their nest egg can grow until it pays enough dividends to cover their future retirement needs.
For example, saving $90,000 at age 30 (assuming an average 7% annual return) will turn into $1 million over 35 years. With the knowledge that a million is waiting for them when they get to 65, that person can live their remaining decades a lot freer.