Calculate Your Investment Growth Over Time with Advanced Features
| Year | Start Balance | Interest | End Balance |
|---|
Compound interest is the interest earned on both your initial investment (principal) and the accumulated interest from previous periods. It is often called "interest on interest" and is one of the most powerful concepts in personal finance and investing.
Let's say you invest $10,000 at 8% annual interest. In year one, you earn $800 in interest, giving you $10,800. In year two, you earn 8% on the full $10,800, not just your original $10,000. That extra interest comes from earning interest on your interest - that is compounding.
Time is the most powerful factor in compound interest. Starting at age 25 versus 35 can mean hundreds of thousands more in retirement savings. Even small amounts invested early can grow to substantial sums due to decades of compounding.
Daily or monthly compounding is standard for most savings accounts. More frequent compounding yields higher returns. Our calculator lets you choose your compounding frequency.
Divide 72 by your interest rate to find how many years it takes to double your money. At 8% interest, 72 divided by 8 equals 9 years to double your investment.
Time is the most powerful factor in compound interest. Even small amounts invested early can grow to substantial sums due to decades of compounding. Starting at age 25 versus 35 can mean hundreds of thousands more in retirement savings.
Yes. A 4% return with 3% inflation gives you only 1% real purchasing power growth. Always consider what your money can actually buy in the future. Our calculator includes inflation adjustment to show real returns.
Simple interest is calculated only on the principal amount. Compound interest is calculated on the principal plus accumulated interest, leading to exponential growth over time. Compound interest always yields higher returns.
Taxes on interest income reduce your effective return rate. If you earn 8% interest and pay 15% tax, your after-tax return is 6.8%. Tax-advantaged accounts like 401(k)s and IRAs can help you keep more of your returns.
Absolutely! Enter your current savings, monthly contribution, expected return rate, and years until retirement. Adjust for inflation and taxes to see realistic projections.