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Inflation: Why Your Money Buys Less Every Year

Inflation is the slow, steady rise in the general level of prices — and the reason a coffee that cost $2 a decade ago costs $3 today. In this short lesson you will learn what causes inflation, how it quietly shrinks the value of cash, and what you can do about it. Then you can test yourself and see the effect in numbers with our calculator.

What inflation actually is

Inflation measures how much more expensive a typical basket of goods and services becomes over time, usually shown as an annual percentage. If inflation is 3%, something that cost $100 last year costs about $103 this year. The flip side is purchasing power: the same $100 in your pocket buys 3% less. Central banks such as the Federal Reserve and the European Central Bank aim for around 2% a year, because gentle, predictable inflation is considered healthier for an economy than falling prices (deflation).

Why prices rise

Prices climb for a few connected reasons. Demand-pull inflation happens when people want to buy more than the economy can produce, so sellers raise prices. Cost-push inflation comes from rising costs of production — energy, wages or raw materials — that businesses pass on to you. And the money supply matters too: when far more money chases the same goods, each unit of currency is worth a little less. Most real-world inflation is a mix of all three.

How inflation erodes savings

Here is the part that matters for your wallet. Money sitting in a zero-interest account loses value every single year in real terms. At 3% inflation, cash loses roughly half its purchasing power in about 24 years (a quick way to see this is the ‘Rule of 72’: 72 ÷ 3 = 24). That is why simply saving is not enough — to protect and grow your money you need a real return (your return after subtracting inflation) that is positive. Assets like stocks, index funds and inflation-linked bonds have historically outpaced inflation over the long run, while cash rarely does.

Key takeaways

  • Inflation is the rise in general prices; 2–3% a year is typical.
  • It quietly reduces the purchasing power of cash.
  • What matters is your real return — return minus inflation.
  • Investing in productive assets is the main defence against inflation.

Quick quiz: test your inflation knowledge

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1. If annual inflation is 3%, what happens to $100 of cash in a year?

2. Which of these best protects money against long-term inflation?

3. What is a ‘real return’?

4. Roughly how long does 3% inflation take to halve your purchasing power?

See inflation eat your money

You have learned the theory — now watch it happen. Enter an amount and a time period to see exactly how much purchasing power inflation takes away.

Open the Inflation Calculator →
Related reading: Understanding inflation (deep dive) Next lesson: Compound Interest →