Compound Interest Visualizer Calculator

Your monthly contribution is always deposited monthly regardless of whether interest compounds monthly, quarterly, daily, or annually, so the two schedules don't naturally line up. The calculator derives an effective monthly rate, (1 + r/n)^(n/12) − 1, from whatever compounding frequency you select, then grows the contribution stream at that equivalent monthly pace using the future-value-of-an-annuity formula — keeping contributions and principal consistent with the same underlying annual rate.

Early on, your future value is dominated by the money you've physically put in, since there's been little time for interest to accrue. As the years pass, previously earned interest itself starts earning its own interest — the compounding snowball — so the interest portion of your balance grows proportionally faster than your contributions do, pushing that ratio steadily upward even though the rate itself never changes.

The yearly balance breakdown used for the growth chart is explicitly capped at a maximum of 50 data points in the underlying calculation, regardless of how many years you enter for the projection. The headline Future Value, Total Contributed, and Total Interest Earned figures are still computed for your full entered time period — only the year-by-year chart visualization is capped.

The Annual Interest Rate is the nominal rate you input. Effective Annual Rate is (1 + r/n)^n − 1, which accounts for interest compounding within the year before the year is over — for example, monthly compounding at a 7% nominal rate produces a slightly higher effective annual yield because each month's interest starts earning its own interest before the year ends. The more frequently interest compounds, the larger this gap becomes.