Passive Income Goal Calculator

It takes the gap between your passive-income goal and what you already receive, annualizes it (multiplies by 12), and divides by your entered annual return rate — treating that rate as if it were a sustainable withdrawal/yield percentage, similar in spirit to the 4%-rule but using whatever percentage you supply instead of a fixed 4%. A higher entered return rate makes the required portfolio look smaller, so an overly optimistic rate will make your goal look closer than it realistically is.

The engine actually simulates monthly compounding of your current investments plus your monthly contribution, checking each year whether the balance has crossed the required portfolio size, capped at 100 years. If your monthly investment is $0 and you still have a gap to close, the simulation can never reach the target, so it returns "Never (increase monthly investment)" instead of an endless year count.

They answer two different questions with two different methods. Years-to-goal simulates your actual entered monthly investment forward until the balance crosses the required portfolio; the 10-year figure independently solves a future-value-of-annuity formula for the level monthly payment that would close the same gap in exactly 10 years. Unless your current contribution happens to match that 10-year pace, the two numbers won't line up — neither one restates the other.

Current passive income is money you already receive each month from investments, rentals, or dividends — it's subtracted directly from your target (monthly expenses times desired coverage percentage) to get the "Additional Monthly Income Needed" the calculator then works backward from. It is a separate input from your current investments figure, which only feeds the portfolio-growth simulation.