Three small tools for the mental arithmetic every investor should be able to do at a dinner table: how fast money doubles, how fast it rots, and how to split it.
Rule of 72
Years to double = 72 ÷ return
Money doubles every
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In 24 years that's
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Inflation's bite
The guaranteed negative return
Today's ₹1,00,000 will buy only
—
To keep today's lifestyle you'll need
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This is why "keeping money safe" in a low-interest account is actually losing it slowly.
Starting-point allocation
The 100 − age rule, adjustable
Suggested starting split
Equity %Debt %
How to read this
A rule of thumb, not a prescription. The real test: if your equity portion fell 40% next year, would you hold on? If not, your true allocation is lower than your theoretical one. Gold (5–10%) can come out of the debt share if you want it.