Compound Interest Calculator
Investment growth with contributions, year-by-year table and visual breakdown.
Final Balance
$144,573
after 20 years
Total Contributions
$58,000
Interest Earned
$86,573
Return on Investment
149.3%
Rule of 72 (yrs to 2×)
10.3 yrs
Get Full Growth Table
Year-by-year balance, contributions, and interest earned.
Frequently Asked Questions
What is compound interest?
Compound interest is interest calculated on both the initial principal and the accumulated interest. Unlike simple interest, it grows exponentially over time.
How often should interest compound?
More frequent compounding means faster growth. Monthly compounding is most common for savings accounts. Daily compounding yields slightly more than monthly.
What is the Rule of 72?
Divide 72 by your annual interest rate to estimate years to double your money. At 6%, money doubles in approximately 12 years.