To determine how much you need in your 401(k) to provide a monthly income of $2000, you'll need to consider factors such as your expected retirement age, life expectancy, and the rate of return on your investments. As a rough estimate, financial planners often use the 4% rule, which suggests you can withdraw 4% of your portfolio each year in retirement. So, to generate $24,000 a year ($2000/month), you might need a 401(k) balance of about $600,000. However, this is a rough estimate; actual amounts can vary based on personal circumstances and market conditions.