See how a starting amount plus monthly savings grows with compound interest.
🔒 Calculated in your browser.
How to use the compound interest calculator
- Enter the starting amount and monthly contribution.
- Set the interest rate, years and compounding.
- Read the final balance and interest earned.
The power of starting early
At 7% a year, money roughly doubles every 10 years. Ten extra years of saving can matter more than a higher contribution later.
Frequently asked questions
What is compound interest?
Interest earned on both your money and the interest it already earned.
What rate should I use?
Use a realistic long-term average for the account or investment; this is not financial advice.
Monthly vs yearly compounding?
More frequent compounding grows slightly faster.