Question 1

What is the Rule of 72?

Accepted Answer

The Rule of 72 is a simple formula to estimate how long it takes for an investment to double given a fixed annual rate of return. Divide 72 by the interest rate percentage to get the approximate number of years.

Question 2

How accurate is the Rule of 72?

Accepted Answer

The Rule of 72 is quite accurate for interest rates between 6% and 10%. For rates outside this range, there are slight variations: Rule of 69.3 for continuous compounding, Rule of 70 for daily compounding, and Rule of 71 for monthly compounding.

Question 3

Can I use the Rule of 72 for any investment?

Accepted Answer

The Rule of 72 works best for investments with consistent compound interest like savings accounts, CDs, bonds, or index funds. It's less accurate for volatile investments like stocks or those with variable returns.

Question 4

What does a 6% return mean?

Accepted Answer

With a 6% annual return, your investment would double in approximately 12 years (72 ÷ 6 = 12). This demonstrates the power of compound interest over time.