What the calculation measures
Current yield reflects today's price; yield on cost relates current dividend to your historical average purchase price.
How to interpret the result
Dividends can be changed, suspended or paid irregularly, so projected annual income is not guaranteed.
Run scenarios instead of one answer
Change the most uncertain input and compare outcomes. A calculator is most useful when it shows sensitivity, not when one estimate is treated as a guarantee.
Limits and assumptions
Tax treatment and withholding depend on account type and jurisdiction.