Monthly Compound Interest Calculator

Monthly compounding calculates and adds interest to your principal twelve times per year instead of once. This means each month's interest begins earning its own interest sooner, resulting in a higher effective annual yield. For example, a 6% annual rate compounded monthly produces an effective rate of about 6.17%.

Banks use monthly compounding because it aligns with monthly statement cycles and provides customers with a competitive effective yield. It strikes a balance between the simplicity of annual compounding and the complexity of daily compounding. Monthly compounding is also easy for consumers to understand alongside monthly deposits and withdrawals.

A $200 monthly contribution at 6% compounded monthly adds approximately $32,776 in contributions plus earned interest over 10 years, on top of the growth from your initial principal. Regular contributions are one of the most powerful ways to build wealth because each deposit immediately begins compounding. The earlier and more consistently you contribute, the greater the impact.