How long a $400,000 retirement fund will last depends heavily on your annual withdrawal rate, lifestyle expenses, investment returns, and geographic location. Using the classic 4% rule as a general guideline, a $400,000 portfolio would provide roughly $16,000 in pre-tax income during the first year, which could theoretically sustain a 30-year retirement if invested in balanced growth assets. However, if withdrawals are higher (such as $30,000 to $40,000 annually), the principal will deplete much faster, potentially lasting only 10 to 15 years. To provide a tailored financial perspective: What is your estimated annual retirement spending, and will you be receiving supplementary income from state pensions or Social Security?