The quietest large number in your finances
Inflation never sends a statement. Your bank balance shows the same figure it did last year, and yet the balance buys less — at 6%, an unspent rupee loses about half its purchasing power every twelve years. That twelve comes from the rule of 72: divide 72 by the inflation rate to get the doubling time of prices. 6% doubles prices in 12 years; 8% in 9.
The calculator above runs both directions at once: what today’s expense will cost after N years, and what today’s rupees will actually buy then. The second number is the one that stings — it is your savings account seen through honest glasses.
₹1 lakh, left alone
Here is what a steady 6% does to a ₹1,00,000 expense — or equivalently, what a ₹1,00,000 note under the mattress quietly becomes. Twenty years is one child’s gap between admission and postgraduation; thirty is a typical working career. Retirement plans that ignore this table are not plans, they are wishes.
| In 5 years | ₹1,33,823 |
| In 10 years | ₹1,79,085 |
| In 20 years | ₹3,20,714 |
| In 30 years | ₹5,74,349 |
One economy, many inflation rates
The headline CPI number is an average across a basket — your personal basket differs, and the differences are systematic. Education inflation in India has run at 8–10% for years: a course that costs ₹20 lakh today will ask for roughly ₹43–52 lakh in ten. Healthcare runs near 10%, which is precisely why a health cover that felt generous at 40 feels thin at 60. Food swings seasonally; fuel follows geopolitics. Electronics actually deflate — the ₹30,000 phone gets better every year, not cheaper groceries.
The planning consequence: use 6% for general goals, but 8–10% when the goal is a child’s education or future medical costs. Slide the rate above and watch a 20-year education goal move — the difference between assuming 6% and 10% on a ₹20 lakh course is the difference between saving for ₹64 lakh and ₹1.35 crore.
Real returns — the only returns that count
Every return you earn has inflation silently subtracted from it. A 7% FD during 6% inflation grows your purchasing power by about 1% a year — and after tax on the interest at slab rate, often by nothing at all. This is the honest case for equity in long-term plans: not excitement, arithmetic. Historically only a few asset classes have out-run Indian inflation by a wide margin after tax, and diversified equity is the accessible one.
A useful discipline: whenever you see a return, mentally subtract 6 before feeling anything. 12% is 6 real. 7% is 1 real. 4% in savings is −2 — a slow leak dressed as safety. Growing income helps too, which is why pairing a rising salary with a step-up SIP is the standard counter to a rising cost of living.