Compound Interest Example
$1,000 Compound Interest — 10 Years Example
See how $1,000 grows with compound interest over 10 years at different rates.
Scenario
$1,000 initial investment, 10 years, monthly compounding.
Inputs
Initial Amount$1,000
Period10 years
CompoundingMonthly
Results
At 5%$1,647
At 7%$2,009
At 10%$2,707
Rule of 72 (doubles at 7% in)~10.3 years
Explanation
At 7%, $1,000 roughly doubles in 10 years — confirming the Rule of 72 (72 ÷ 7 ≈ 10.3 years). At 10%, it nearly triples. The key insight: the rate of return matters enormously over a decade.
Key Takeaways
- Rule of 72: divide 72 by your interest rate to find years to double.
- Tax-advantaged accounts (Roth IRA) let this compound tax-free.