Number of Periods Calculator: Determine Annuity Duration Easily

Enter your target balance, interest rate, and payment size—our calculator instantly shows how many deposits you need. Raising the periodic rate by just 1 percentage-point can cut payoff time about 15 % for typical consumer loans (Federal Reserve, 2022). Powered by the standard logarithmic annuity formula, the tool clarifies timelines so you can budget with precision.