The $10,000 that stayed $10,000
In 1945 ten thousand dollars was a fortune. It bought a comfortable house outright, with a new car left over. A family that sealed those notes in a tin and buried them in the garden would dig up the same ten thousand dollars today — enough for a second-hand car and not much else. Nothing was stolen. The number never changed. What changed was the price of everything the money was meant to buy.
That is inflation erosion, and it is the most reliable financial force of the last century. US consumer prices have risen roughly eighteenfold since the end of the war, which means a dollar from 1945 has surrendered about ninety-four per cent of its buying power. The erosion happens a few per cent at a time, too slowly to feel and too steadily to escape.
Cash, gold, shares and bricks: the eighty-year race
The calculator above runs the same starting sum through five very different homes. Cash under the mattress is the control: zero growth, full erosion. A savings account paying a long-run average of around 3.4% barely stays level with inflation once tax is taken, which is why deposit accounts preserve money rather than grow it.
Gold spent the first quarter of the period pinned near $35 an ounce by the Bretton Woods system. When Nixon severed the dollar's link to gold in 1971 the price was released, and it has since risen roughly a hundredfold — a superb inflation hedge in hindsight, though it paid nothing along the way and fell for the whole of the 1980s and 1990s.
Shares tell the most dramatic story. The S&P 500 with dividends reinvested has compounded at roughly 11% a year since 1945, and eighty years of compounding at that rate turns a modest sum into a generational one. UK shares grew handsomely too, though the FTSE has trailed Wall Street badly since the mid-1990s. Property sits in between: reliable growth in the price of the bricks, before you add rental income or subtract maintenance, insurance and interest.
Nominal versus real: why the toggle matters
A nominal return is the number on the statement. A real return is what is left after inflation has taken its cut, and it is the only figure that tells you whether you are actually better off. An investment returning 6% in a year of 6% inflation has earned you precisely nothing, however good the headline looks.
Switch the calculator to adjusted for inflation and every result is restated in the money of your starting year. Cash visibly shrinks. The savings account flattens out. Gold and property hold their shape. Shares stay enormous — because a real return of seven or eight per cent a year, sustained for decades, is the closest thing to financial magic that exists.
Rules of thumb worth remembering
- The rule of 72. Divide 72 by the inflation rate to find how many years it takes for prices to double. At 3% that is 24 years; at 6% just 12.
- Cash is a short-term tool. Emergency money belongs in cash. Money you will not touch for a decade loses far more to erosion than it ever gains in safety.
- Time beats timing. Nearly all the difference between the lines on the chart comes from how long the money compounded, not from clever entry points.
- Real returns are the scoreboard. Judge every account, fund or property by what it earned above inflation, after tax and fees.
Frequently asked questions
- What is $10,000 from 1945 worth today?
- Left as banknotes, $10,000 from 1945 is still $10,000 — but US prices are roughly 18 times higher, so it buys about $560 worth of 1945 goods. To match the purchasing power of that 1945 sum you would need close to $180,000 today.
- Which asset protected money best since World War II?
- Shares, by a wide margin. $10,000 in the S&P 500 with dividends reinvested since 1945 compounds into tens of millions of dollars, far ahead of gold, UK shares and US housing. Gold protected purchasing power but produced no income; cash lost the most.
- How does inflation erode savings?
- Inflation raises the price of everything you buy while the number in your account stays the same. At 3% a year, money loses about a quarter of its buying power in ten years and more than half in twenty-five. The loss is invisible on a bank statement, which is why it is called erosion.
- What does 'adjusted for inflation' mean on this calculator?
- The toggle restates every result in the purchasing power of your starting year. A nominal figure tells you how many dollars you would hold; the inflation-adjusted figure tells you how much stuff those dollars would actually buy compared with the year you started.
- Is gold a good hedge against inflation?
- Over very long spans gold has roughly kept pace with prices, which is what a hedge is meant to do. But it was fixed by law near $35 an ounce until 1971, then surged, then fell for two decades. It preserves value in fits and starts and pays no dividend or rent.
This tool is for education and curiosity, not financial advice. Historical returns are approximations built from public long-run series and say nothing about future ones. Investments can fall as well as rise.