Compound Interest Calculator
Small savings. Bigger possibilities.
See how your savings or investments could grow over time. Enter your starting amount, monthly contributions, interest rate and time horizon to explore the power of compounding.
💵 Enter your savings details
💡 Enter a hypothetical annual interest rate. This calculator assumes a constant rate compounded monthly, with contributions added at the end of each month.
⚙️ How this calculator works
Interest is calculated monthly using your annual rate divided by 12. Your balance earns interest, then your monthly contribution is added. The process repeats for the selected number of years.
The calculation excludes taxes, inflation, investment fees and changes in market returns. Selecting a different currency changes the display only; it does not convert amounts.
✨ Your savings projection
📊 How your savings could grow
The blue portion represents money you’ve contributed. The green portion represents compound growth.
🧠 What is compound interest?
Compound interest is interest earned on both your original money and interest accumulated in previous periods. As your balance grows, the amount of interest it can generate also grows.
Regular contributions can increase your future balance significantly. The earlier you begin, the more time your money has to compound.
🧮 Example: Investing every month
Imagine starting with $1,000 and adding $100 at the end of every month for 20 years, earning a hypothetical 6% annual interest rate compounded monthly.
Your initial deposit and contributions total $25,000. The remaining balance comes from compound growth.
💡 Frequently Asked Questions
Simple interest is calculated on the original principal. Compound interest is calculated on the principal plus previously accumulated interest.
Yes. Regular contributions increase the amount invested, and those additional deposits can also earn interest over time.
This calculator uses monthly compounding. Actual savings accounts, loans and investments may use different compounding schedules or return assumptions.
No. Results are shown in nominal currency values before taxes, fees and inflation. Your purchasing power in the future may be lower than the displayed balance suggests.