See exactly how your money grows over time. The eighth wonder of the world — visualized.
Model any investment scenario — savings account, index fund, or retirement portfolio.
Compound interest means you earn interest on your interest — not just your original investment. Over decades, this creates exponential growth. A one-time $10,000 investment at 7% annual return grows to over $76,000 in 30 years without adding a single dollar. Add $500/month and it grows to nearly $600,000.
To quickly estimate how long it takes your money to double, divide 72 by your annual return rate. At 7%, your money doubles every ≈10.3 years. At 10%, every ≈7.2 years. At 4% (a high-yield savings account), every ≈18 years.
Someone who invests $200/month from age 22–32 (10 years) and then stops will have more at age 65 than someone who invests $200/month from age 32 to 65 (33 years) — at the same 7% return. Starting a decade earlier is more powerful than contributing for three times as long.