Why Compounding is Called the Eighth Wonder
At 7% annual returns, $10,000 grows to approximately $19,700 in 10 years, $38,700 in 20 years, and $76,100 in 30 years. The first decade adds $9,700, but the final decade adds $37,400. This acceleration is the essence of compounding: growth builds upon growth in an exponential curve. The longer money compounds, the more dramatic the results become.
Three Factors That Drive Compounding
Compounding depends on principal, rate of return, and time. Time is the most powerful lever. Starting at age 20 with $300 monthly at 5% yields approximately $458,000 by age 60. Starting at 30 yields $250,000; at 40, just $124,000. A ten-year head start nearly doubles the outcome. The saying 'the best time to invest was 20 years ago, the second best time is today' is backed by compounding mathematics.
Three Enemies of Compounding
Fees, taxes, and inflation erode compounding's power. A 1.5% annual fee on a 7% return reduces 30-year growth from $76,100 to $49,800 on a $10,000 investment. Taxes on dividends and capital gains further reduce the compounding base. Inflation diminishes the purchasing power of accumulated wealth. Maximizing compounding requires low-cost index funds in tax-advantaged accounts held for decades.