What living off dividends takes
Start from the expense, not the portfolio. If you need $5,000 a month after tax, that is $60,000 a year, and at a 3.8% yield taxed at 15% it takes roughly $1.86 million to produce. Raise the yield to 5% and the requirement drops near $1.4 million. Those two numbers are the entire debate in dividend retirement, and most of the arguing is about whether the higher yield is real or borrowed from future growth.
The calculator above works the problem from the other end. Enter your current balance, monthly contribution, and income goal. It marks the crossover year: the first year projected income covers the goal in today's dollars. Inflation is doing real work in that sentence. A plan that hits $5,000 a month in 2050 has not hit today's $5,000 a month unless you deflated it, and plenty of retirement projections quietly skip that step.