Compound Interest Calculator
Watch your investments grow over time. See how regular contributions and compound interest work together to build wealth.
Investment Details
Starting amount
Amount you add each month
Typical range: 3% - 10%
10 years
Final Amount
Total Value
$106,639.02
Initial Investment
$10,000.00
Total Contributed
$70,000.00
Interest Earned
$36,639.02
Total Contributed
$70,000
Interest Earned
$36,639
Interest as % of Total
34.36%
What Makes Up Your Final Amount
Your Investment Timeline
đź’ˇ Tip: The longer you invest, the more compound interest works in your favor. Even small monthly contributions add up over time.
How Compound Interest Works
Understanding Your Inputs
Initial Investment: The amount of money you start with. This is your opening balance.
Monthly Contribution: The amount you add to your investment each month. Regular deposits accelerate growth significantly.
Annual Interest Rate: The yearly percentage return on your investment. This compounds monthly, meaning you earn interest on your interest.
Time Period: How long you let your money grow. The longer the timeline, the more powerful compound interest becomes.
What This Calculator Shows
- Your total contributions (initial + monthly deposits)
- Interest earned through compound interest
- Final amount after interest compounds
- How much of your growth comes from interest vs. contributions
The Power of Time
Compound interest is called "the eighth wonder of the world" for a reason. The longer your money sits, the more it grows:
- 10 years: Compound interest adds moderate growth
- 20 years: Growth accelerates noticeably
- 30+ years: Interest can exceed your contributions
- Higher rates: Even small percentage increases have huge long-term impact
Investment Tips
- Start early—time is your biggest advantage with compound interest
- Be consistent—regular monthly contributions are more important than one-time deposits
- Small amounts add up—even $100/month becomes significant over decades
- Don't withdraw early—removing money cuts short the compounding process
- Compare rates—even 1% difference compounds to substantial amounts over time
Compound interest calculator updated: 2026