Enter a starting amount, interest rate, and number of years to see how your money grows with compound interest, with an optional monthly contribution.
Starting amount ($):
Annual interest rate (%):
Years:
Compounds per year:
Monthly contribution ($, optional):
How It Works
The calculator applies interest period by period based on how often it compounds, adding any monthly contribution along the way, and totals the final balance, contributions, and interest earned.
How to Use This Tool
- Enter your starting amount, interest rate, and number of years.
- Leave compounds per year at 12 for monthly compounding, or change it if you know your account compounds differently.
- Optionally add a monthly contribution, then click Calculate.
This assumes a constant interest rate for the whole period, which is a simplification; real investment returns vary year to year.
Did You Know?
- Compound interest means you earn interest on your interest, not just on your original deposit, which is why growth accelerates over time.
- Starting even small regular contributions early can outperform larger contributions started later, thanks to the extra time compounding has to work.
Frequently Asked Questions
Is this financial advice?
No, this is a general math calculator, not personalized financial advice. Talk with a financial advisor for guidance specific to your situation.
What does “compounds per year” mean?
It is how often interest is calculated and added to your balance each year, commonly 12 (monthly) for savings accounts, but sometimes daily, quarterly, or annually.