The Rule of 72 estimates doubling time by dividing 72 by the annual rate of return. At 8% per year, money roughly doubles in 9 years; at 12%, in about 6 years.
It is an approximation and works best for rates between 6% and 10%. Actual market-linked returns vary and are not guaranteed.
Illustrative only. This article is for education only and is not investment advice.