Compound Interest Calculator
Enter your principal, rate, and time to see how compounding grows your money.
Results
Final Amount
$20,096.61
Principal
$10,000.00
Interest Earned
$10,096.61
Effective APY
7.23%
Total Growth
101.0%
How Compound Interest Works
Compound interest means you earn interest on your interest — not just on your original principal. Over time, this creates exponential growth. For example, $10,000 at 7% compounded monthly for 30 years grows to over $81,000, compared to just $31,000 with simple interest.
The formula is: A = P(1 + r/n)^(nt) where P is principal, r is the annual rate, n is the number of times interest compounds per year, and t is time in years.
More frequent compounding (daily vs. annually) produces slightly higher returns through the effective APY, which this calculator computes for you automatically.