Compound Interest Calculator

How We Calculate Your Results

Interest Compounding: Your investment earns interest that compounds at the end of each compounding period you select (Monthly, Quarterly, Semi-Annually, or Annually). This means the interest is calculated and added to your principal at the end of each period, and then future interest is calculated on the new, larger balance.

Contribution Timing: You can choose when contributions are applied - either at the beginning or end of each month. This setting allows you to match different financial scenarios:

• Beginning of Period: Contributions are added at the start of the month and earn interest for the entire period (common for automatic savings plans)
• End of Period: Contributions are added at the end of the month after interest is calculated (conservative approach)

Note: The timing you select can make a noticeable difference in results. Beginning-of-period contributions typically earn more because they have more time to compound.

Contribution Frequency Conversions: When your contribution frequency differs from your compounding period, we convert contributions proportionally. For example:

• Weekly contributions: Your annual contributions (52 weeks) are divided across 12 months, resulting in 4.33 weeks per month
• Bi-weekly contributions: Your annual contributions (26 periods) are divided across 12 months, resulting in 2.17 periods per month
• Monthly contributions: Applied directly as specified
• Annual contributions: Divided evenly across 12 months

Display Format: Results are shown by compounding period. The year-by-year breakdown displays annual snapshots of your investment growth, making it easy to track your progress over time.

Note: These calculations are for educational and planning purposes only. Actual investment returns may vary due to market conditions, fees, taxes, and other factors not included in this simplified model.