New Delhi, April 15 -- Have you ever wondered how long it will really take for your money to double in safe investments such as PPF, FDs, Sukanya Samriddhi Yojana (SSY), Senior Citizen Savings Scheme (SCSS) or Post Office savings schemes? The answer to this question lies in a simple yet effective financial formula known as the Rule of 72.

The Rule of 72 helps investors quickly estimate how much time it will take for their wealth to grow. This way, this formula can also be used to compare fixed-income options for a rough estimate of their performance and investment viability.

Furthermore, the data obtained from such a comparison can be used to plan long-term financial investments based on well-thought-out economic goals, without complexi...