Compound Interest Example
Save $500/Month — 20-Year Compound Growth
How $500/month grows to over $260k in 20 years with 7% compound interest.
Scenario
$500/month at 7% APY, monthly compounding, 20 years.
Inputs
Monthly$500
Rate7%
Period20 years
Results
Final Balance$261,985
Total Contributed$120,000
Total Interest$141,985
Explanation
$500/month for 20 years at 7%: you put in $120k and get back $262k. The market does more work than you do — interest ($142k) exceeds contributions ($120k). This is a realistic 401(k) scenario for many earners.
Key Takeaways
- $500/month is ~6% of a $100k salary — below the 10–15% recommended savings rate.
- Max out employer 401(k) match first — that's an instant 50–100% return.