Why is my money worth less even though it grew?Start here

Two numbers are moving. The one on your statement, and the one on the price tags. Only the gap between them is a return.

Your balance went from 10,000 to 11,000 over three years. That is 10% more money. Whether it is 10% more anything else depends on what happened to prices in the same three years — and if they rose 12%, you can buy less than you could before.

What is the difference between nominal and real?

The nominal return is the number on the statement. The real return is what is left after prices are taken into account, and it is the only one that says anything about what you can actually do with the money.

The quick version is to subtract: 5% growth minus 3% inflation is about 2% real. The exact version divides, which matters when the numbers get large — 50% growth against 40% inflation is not 10% real, it is about 7%.

Everything you read is quoted nominally by default. That is the convention, and it is why real returns feel like bad news: they are the same fact, stated honestly.

How bad is it for cash?

Worse than it feels, because it happens slowly and never triggers anything. At 3% inflation, money left under the mattress loses about a quarter of its purchasing power in ten years and about half in twenty-three.

A savings account paying less than inflation is losing purchasing power too, just more slowly. The balance never goes down, which is exactly why the loss is so easy to miss. Inflation has the calculator; putting in your own numbers is a useful five minutes.

Which investments actually keep up with prices?

Fewer than the marketing suggests, and the honest answers are qualified.

• Inflation-linked bonds are the only instrument that does it by contract. The principal itself is adjusted to the official price index. Everything else is a correlation, not a promise.
• Shares keep up over long periods, because companies raise their own prices. Over short periods they often do the opposite, because rising inflation tends to bring rising rates, which knocks prices down first.
• Property and infrastructure often have rents or tariffs linked to inflation in writing. Check the contract rather than the category.
• Gold has kept up across centuries and lost badly across decades. It is a store of value on a timescale longer than most people's plans.

Does inflation change the tax I pay?

Yes, and against you. Tax is charged on the nominal gain, not the real one. Buy at 100, sell at 130 after prices rose 30%, and you have gained nothing at all in purchasing power — but you owe tax on 30.

In high-inflation periods this quietly turns modest real gains into real losses after tax. It is one of the reasons inflation is described as a tax in itself.

Why does 2% keep getting mentioned?

Because most large central banks target about 2% inflation, and shape interest rates around hitting it. Not zero: a small, predictable amount of inflation is thought to be safer than risking prices falling, which brings its own problems.

So a slow loss of purchasing power on idle cash is not a malfunction of the system. It is roughly the intended state of it. Monetary policy is the page on why.

What is the practical version?

When you see a return, ask what inflation was over the same period, and subtract. Do it for your savings account too. The point is not pessimism — it is that the comparison you actually care about was never between 0% and 5%, but between 5% and whatever the price tags did.