How Long to Turn ₹1 Lakh into ₹2 Lakh? The Rule of 72 Explained with a Handy Table

What is the Rule of 72?

The Rule of 72 is a quick and simple formula used to estimate how long it will take for an investment to double at a fixed annual rate of interest. You divide 72 by the annual interest rate (in percentage terms), and voilà, you get the approximate number of years for your money to double.

Formula of the Rule of 72

The formula is:Years to Double = 72/Interest Rate

For instance, if the interest rate is 12%, your investment will double in approximately:
72/12=6 years

How Long for ₹1 Lakh to Become ₹2 Lakh?

If you invest ₹1 lakh at different interest rates, the Rule of 72 helps you estimate the time it takes to double your investment.

Here’s a table showing the doubling time for interest rates from 8% to 14%:

Key Observations from the Table

1. Higher Interest Rates Reduce Doubling Time:
   At 8%, it takes 9 years to double ₹1 lakh, while at 14%, it takes just 5.14 years.
2. Small Increases in Interest Rates Have Big Impacts:
   A shift from 10% to 12% reduces the doubling time by more than a year.
3. Compounding Works Wonders Over Time:
   The faster your investment doubles, the more cycles of compounding you benefit from.

Why is the Rule of 72 Useful?

The Rule of 72 offers a quick, no-fuss way to estimate growth. Whether you’re planning long-term investments or simply comparing financial products, it’s a handy tool to gauge how effectively your money can grow.

Disclaimer: This blog has been written exclusively for educational purposes. The securities mentioned are only examples and not recommendations. This does not constitute a personal recommendation/investment advice. It does not aim to influence any individual or entity to make investment decisions. Recipients should conduct their own research and assessments to form an independent opinion about investment decisions. 

Mutual Fund investments are subject to market risks, read all scheme-related documents carefully.