What Is Inflation? Explained With a Chocolate Bar

A woman cleaning a house in the UK recently found something odd: a sealed Mars bar with a best-before date of 1991, intact 35 years later. Placed next to a current bar, the old one was clearly bigger. The comparison went viral — and, without meaning to, it's one of the best economics lessons you'll ever see in a one-minute video.

What Inflation Is, in One Sentence

You don't need an economics textbook. The idea fits in one line: over time, the same banknote buys less and less. It's not that chocolate "is worth more" in some cosmic sense; it's that your money is worth less, so it takes more coins to buy the same thing.

That's why your grandparents say "a single coin bought a whole pile of sweets." They're not (much) exaggerating: the price of almost everything rises, decade after decade, slowly but relentlessly.

Prices Then and Now

Concrete examples make it tangible. These are approximate reference figures in the UK, to give a sense of the scale of change over about three decades:

The postage stamp is the list's champion: multiplied about seven times. But the pattern is always the same — prices rise, and what was pocket change 35 years ago is a figure you feel today. Not because the products got seven times better, but because money got cheaper.

The Extra Trick: Shrinkflation

Here's the sneakiest part, the one the Mars bar shows so well. Sometimes a product's price does not rise that much… but the product shrinks. The 1991 bar weighed 62.5 grams; today's, about 40. That's 36% less chocolate — but on the shelf it still looks like "a normal Mars bar."

This is called shrinkflation: instead of raising the price visibly, the company reduces the quantity and keeps the price similar. The effect on your wallet is the same as inflation — you pay more per gram — but it's harder to notice. That's why the video went viral: put the two bars side by side and you suddenly see inflation, which is normally invisible.

How Much Would Something You Bought Years Ago Cost Today?

This is where it gets genuinely fun: thinking about your own memories. How much did you pay for your favourite childhood sweet? For a cinema ticket, an ice cream, your first phone? Adjusted for inflation, today's figure almost always surprises — sometimes upward (things that rose faster than inflation) and sometimes downward (electronics especially, which tend to fall).

Doing that sum is a curious pastime and, along the way, an intuitive way to feel how much money's value has shifted. A price change calculator tells you instantly how much the price of anything you remember has changed — and how quietly your purchasing power slipped away.

The Takeaway

A chocolate bar forgotten in a drawer for 35 years ended up being a perfect reminder of how money works: prices rise, products sometimes shrink, and the same banknote buys a little less every year. It's not a catastrophe or a scam — it's inflation, the slow, constant background of every economy. The only unusual thing about this case is that, for once, you could see it, wrapped in paper and dated 1991.

The 35-year-old Mars bar find (best-before date 1991, 62.5 g versus today's ~40 g) was reported by UK media following the viral video of the person who found it. The historical prices are approximate reference figures to illustrate the scale of change, not official figures for each product. Informational and for entertainment.