FIRE

The core idea is a target portfolio roughly 25 times your annual spending, from which you withdraw about 4% a year. Spend $40,000 a year and the number is $1m. Spend $80,000 and it is $2m.

The 4% figure comes from historical US market data and is a planning heuristic, not a guarantee - sequence-of-returns risk means the first few years matter disproportionately. Most people who reach FIRE keep earning something anyway.