Result
Months to goal
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This calculation is for informational purposes only and does not replace advice from a qualified professional. Formulas and rates may not fit your exact situation — double-check the figures before making decisions.
How it is calculated
The calculation solves the future-value-of-an-annuity formula for time: if x = (target amount × monthlyRate + contribution) ÷ (starting capital × monthlyRate + contribution), then months = ln(x) ÷ ln(1+monthlyRate), where monthlyRate is the annual rate ÷ 12 ÷ 100. This is the same math as Excel's NPER function.
If the expected return is 0%, the formula simplifies to months = (target amount − starting capital) ÷ monthly contribution — plain division, no interest.
If the goal simply isn't reachable with the numbers entered (the contribution and return together don't cover the gap between the goal and the starting capital), no result is shown — lower the goal, raise the contribution, or allow more time for the return to compound.