After tax and inflation, safe can go backwards

An uncle cornered me at a wedding last month to tell me his fixed deposit had doubled his money in ten years. Proud of it. And he was right, sort of. The rupees did roughly double. What I did not have the heart to say over the buffet is that the part that matters, what those rupees can actually buy, barely moved.

Here is the part the statement never shows you.

A 7 percent FD does not pay a 7 percent return. If you are in the top tax slab, 30 percent of that interest goes to tax every year, so you are really earning 4.9. Then inflation running near 5 percent quietly takes the rest. What is left, the real return, is roughly zero. For a top-slab saver it actually tips slightly negative.

The cruel part is what it looks like. The same 7 percent FD pays three different people three different real returns. A 5 percent slab saver keeps about +1.65 percent in real terms. A 20 percent slab saver keeps +0.60. A 30 percent slab saver lands at minus 0.10. Same poster rate. Your tax slab decides whether safe is even keeping up with prices.

Put numbers on it. Ten lakh parked for ten years at the top slab grows to about 19.67 lakh on the statement. Feels like it doubled. Strip the tax and the inflation and the purchasing power is around 9.9 lakh. Less than the lakh you started with, in real terms.

This is not an argument against fixed deposits. It is an argument against using one for the wrong job. An FD is a parking spot. Perfect for your emergency fund and money you need in a year or two, where not falling is the whole point. It is a poor engine for a twenty-year goal, where erosion compounds against you the same way growth would have compounded for you.

The honest version: an FD never shows you a loss. That is exactly why it is the easiest place to lose money slowly.

Today's numbers, not round ones

The wedding conversation used round figures. Here are the current ones, so the arithmetic is anchored to something you can look up.

Inflation on the new CPI series was 4.82 percent in Aug 2026, by the MOSPI release of 14 Sep 2026. The RBI's own target is 4 percent, with a band of 2 to 6 percent. Fixed deposit rates tend to move with the repo rate, which the RBI raised to 5.50 percent on 7 Oct 2026.

The 7 percent FD, slab by slab

Take a 7 percent deposit and 4.82 percent inflation. Step one: take the tax off the interest. Step two: take inflation off what is left. The honest way to do step two is to divide, not subtract:

Real return = (1 + after tax return) / (1 + inflation) minus 1.

For the top slab: 7 x (1 minus 0.30) = 4.90 percent after tax. Then 1.049 / 1.0482 minus 1 = 0.08 percent. For someone in the 10 percent slab: 7 x 0.90 = 6.30, then 1.063 / 1.0482 minus 1 = 1.41 percent.

At 4.82 percent inflation the top slab saver is roughly at zero. At the 5 percent inflation in the opening, the same saver tips just below zero. The difference between those two is small. The direction is the point: for the highest slab, a 7 percent deposit is close to standing still in what the money can buy.

Your own deposit, live

Ten lakh for ten years at the top slab becomes about Rs 16.13 lakh after tax. In today's rupees that is about Rs 10.08 lakh. Ten years of waiting bought almost nothing extra. The statement in the opening showed Rs 19.67 lakh because it is the pre tax figure, which is the number most people look at.

Parking spot or engine

None of this makes a deposit a bad product. It makes it a product with a job.

I keep this split in mind whenever I look at a family balance sheet. The question is never whether a deposit is safe. It is whether it is safe for that particular job.

The free Learn module on bonds and fixed income in India covers deposits, government bonds, duration and how rate moves change their value, with quizzes and a certificate. The three number version of this idea is in real against nominal return, and the long horizon side in time diversification.