Compound Interest Calculator

Calculate compound interest with periodic contributions and see detailed growth projections

Initial Investment ($)

Annual Contribution ($)

Monthly Contribution ($)

Interest Rate (% per year)

Time Period (years)

Compound Frequency

Contribution Timing

About Compound Interest

Compound interest is the addition of interest to the principal sum of a loan or deposit, or in other words, interest on interest. It is the result of reinvesting interest, rather than paying it out, so that interest in the next period is then earned on the principal sum plus previously accumulated interest.

The Rule of 72: To find the number of years required to double your money, divide 72 by the annual interest rate. For example, at 6% interest, it will take approximately 12 years (72 ÷ 6 = 12) to double your investment.