Question

At 6.5 percent interest how long does it take to double your money to quadruple it

Answer 1

Your money will double in approximately 11 years and quadruple in approximately 22.

Use the Rule of 72 for doubling (72/interest rate= number of years to double) and the Rule of 144 to quadruple (144/interest rate= number of years to quadruple).

Answer 2

The rule of 72 is a simple way to determine approximately when will someone's investment double.

The formula for applying the rule of 72:

number of years = 72 / interest rate = 72 / 6.5 = 11.08 ≈ 11 years

if we want to know approximately when our investment will quadruple, we just multiply 11.08 x 2 = 22.16 ≈ 22 years