Want the full breakdown? Read Compound Interest: Complete Guide
Calculator#
Compound Interest Calculator
See how your money grows over time with compound interest
Your Investment Growth
Final Balance
$0
Total Contributions
$0
Interest Earned
$0
Contributions
Interest Earned
50%
50%
Growth Over Time
Input Fields#
| Field | What to Enter | Typical Values |
|---|---|---|
| Initial Investment | Starting lump sum | $0 - $50,000 |
| Monthly Contribution | Regular monthly amount | $100 - $2,000 |
| Time Period | Years to grow | 10 - 40 years |
| Annual Return | Expected yearly return | 5% - 10% |
| Compounding Frequency | How often interest compounds | Monthly (most common) |
Tip
Use 7% for inflation-adjusted S&P 500 returns. Use 10% for nominal (before inflation).
Example#
| Input | Value |
|---|---|
| Initial | $5,000 |
| Monthly | $500 |
| Years | 25 |
| Return | 7% |
| Frequency | Monthly |
Result: $436,311 final balance — $155,000 contributed, $281,311 earned from compounding.
Quick Tips#
- Be conservative — Markets don't return 7% every year
- Account for inflation — $436K in 25 years buys less than $436K today
- Factor in fees — 1% annual fees cost tens of thousands over decades
- Start now — Time matters more than timing
Related Calculators#
- FIRE Calculator — When can you retire?
- SWR Calculator — Safe withdrawal rates
- Emergency Fund Calculator — How much safety net?
Learn the math: Compound Interest: Complete Guide
Disclaimer: This calculator reflects my personal views and is for educational purposes only. It is not financial advice. Every situation is different. Always check your country's specific tax and investment rules before acting. See the full Disclaimer and Privacy Policy for the long version.
