Compound Interest Calculator

Compound interest is interest calculated on both the initial principal and the accumulated interest from previous periods. This creates exponential growth rather than linear growth from simple interest.

The more frequently interest compounds, the higher the returns. Daily compounding yields slightly more than monthly, which yields more than annual. The difference is typically small for standard interest rates but grows more significant at higher rates.

The Rule of 72 is a quick way to estimate how long it takes to double your money. Simply divide 72 by the annual interest rate. For example, at 6% annually, money doubles in approximately 72/6 = 12 years.

No, this calculator shows nominal returns without adjusting for inflation. To estimate real returns, subtract the expected inflation rate from your interest rate. For example, if your rate is 6% and inflation is 2%, your real return is approximately 4%.

Regular monthly contributions significantly amplify compound interest growth. Each contribution immediately starts earning compound interest. Even small monthly amounts — like €100/month — can dramatically increase your final balance over long time horizons.

Simple interest is calculated only on the original principal, while compound interest is calculated on the principal plus previously earned interest. That is why compound interest usually leads to faster long-term growth.