Unlocking Wealth

6 Personal Finance Formulas to Retire Early and Rich

Dec 28, 2022

Rajeev Kumar

Time and return on investment are the two key ingredients of successful investing. But how much time and returns will you need to retire early and rich? Let’s find out

The 50-20-30 rule

The rule requires you to keep 50% of your post-tax salary for household expenses, 20% for short term goals, including money for a rainy day, and 30% for long term goals.

The 15-15-15 rule

This is a how to be a crorepati equation.  It requires an investor to save  Rs 15,000 per month for a duration of 15 years in an instrument that generates a 15% return.

Rule of 72

Rule of 72 is used to calculate the time it takes to double your money. Dividing 72 by expected interest rate will give you an idea of the time it will take to double your investment.

Rule of 114

Rule of 114 is used to calculate the time taken to triple your money. Dividing 114 by the expected ROI will give the desired period.

Rule of 144

The time it will take to quadruple your money can be found by dividing 144 by the expected ROI.

100 minus age

This rule is prescribed for asset allocation. Your age needs to be subtracted from 100 to arrive at a number that tells you your allocation in equities.


The mathematical rules of personal finance can help you in money management, investment planning and meeting various financial goals.