Trailing yield, income on cost, and the shares needed for a target payout. All maths runs in your browser.
Trailing yield divides this year's dividend by today's price, so it rises when a stock falls — a high yield is often a warning, not a gift. Yield on cost divides this year's dividend by what you actually paid. Buy at $30, and $1.20 a share is a 4.00% yield on cost. If the holding then doubles to $60 while the payout stays at $1.20, the trailing quote says 2% but your cost basis still returns 4.00% — and only the second number describes the income stream you built.
Taxes, which are withheld at source for many cross-border investors and are usually the single largest drag on dividend income. Also ignored: payout cuts, which are exactly what happens to the highest-yelling yields, and share-count dilution if you reinvest nothing. A dividend is not a return — it is a transfer from the share price to your cash balance, and it only counts if the business keeps earning enough to refill it.
It assumes the current payout holds flat forever. Treat it as a floor: to double your income you need roughly double the capital at the same yield, which is why buying yield with a leveraged or unrepeatable payout is a bad trade.