Compound interest is often called the eighth wonder of the world — small consistent contributions grow into serious wealth over decades. Enter your starting balance, monthly contribution, expected return, and horizon.
Long-term US stock market returns have averaged about 10% before inflation, roughly 7% after. Diversified portfolios blend stocks and bonds and tend to produce lower expected returns with lower volatility.
A quick shortcut: divide 72 by the annual return to estimate how many years it takes for money to double. At 8%, roughly 9 years.
Yes — APY compounding is the same math applied to a lower rate. A high-yield savings account at 5% APY roughly doubles cash in about 14 years, ignoring inflation.