Compound Interest Calculator

The Compound Interest Calculator helps you estimate compound growth for savings and investment scenarios. Enter the principal, monthly contribution amount, bonus contributions, annual interest rate, investment period, and compounding frequency to calculate the final asset value, total contributions, and interest earned.

Year-by-year growth is visualized in a bar chart with a detailed breakdown table, making it easier to compare contribution amounts, rates, years, and compounding frequency. CSV export lets you organize the yearly results in spreadsheet software. The form also supports bonus-month contributions, so regular monthly saving and additional lump-sum contributions can be modeled separately.

The result is an estimate based on a constant assumed return. Taxes, fees, price fluctuations, and principal loss risk are not included, so the output does not guarantee the result of any financial product. For related calculations, use [Present Value Calculator](/en/data/present-value-calculator/) to discount future cash flows, [Simple Interest Calculator](/en/data/simple-interest-calculator/) to compare non-compounded interest, and [Savings Goal Calculator](/en/data/savings-goal-calculator/) to work backward from a target amount.