Saving
Real return is what a savings account pays after prices have moved
The rate on the account is a nominal figure. What it buys depends on what happened to prices over the same period.
There is a short answer about real returns on cash and a useful one, and they are not the same. What follows is the useful one.
The short version
- A positive interest rate can still lose purchasing power.
- Real return is approximately the rate minus the change in prices.
- Cash is not risk-free; it carries the risk that prices rise faster.
Nominal and real are different measurements
The rate advertised on a savings account describes how many more units of currency you will hold at the end of the term. It says nothing about what those units will buy, which depends entirely on how prices moved over the same period.
Subtracting the change in prices from the interest rate gives a rough approximation of the real return, and that figure is often negative. A period of high headline rates can therefore be worse for savers than a period of low ones, if prices rose faster still. This is why comparing this year's rate against last year's tells you very little about how well cash is actually doing.
The arithmetic in plain terms
If an account pays interest at some rate and prices rise by more, the balance grows while the shopping it covers shrinks. The loss is silent because the statement shows a larger number every year and never shows the smaller basket behind it. Across a single year the effect is usually modest, which is precisely why it is so easy to ignore.
Sustained across a decade the same gap compounds, and an untouched balance can lose a substantial share of its purchasing power. The mechanism is identical to compounding but running against you, which is the part most people find counterintuitive.
Why cash is not risk-free
Cash carries no risk of a fall in the stated balance, which is what people usually mean when they describe it as safe. It carries a different risk instead: that the balance stays intact while the cost of whatever it was saved for rises past it. For money needed within a year or two that risk is small and the certainty is worth having, which is the case for emergency reserves.
For money intended to last decades, the same characteristic that makes cash predictable makes it unlikely to keep pace with prices. Describing cash as safe without specifying safe from what is the source of most of the confusion in this area.
Measuring against your own prices
The published measure of price change reflects an average basket, and no household actually buys the average basket. A household whose spending is dominated by rent, energy or childcare experiences a different rate of increase from the published one.
That means the real return on your savings is personal, and the published figure is only an approximation of it. Where money is saved for something specific, the relevant comparison is the price of that thing rather than prices in general.
A deposit saved against house prices and a holiday fund saved against travel costs are two completely different races.
What can be done about it
Making sure the rate is competitive is the part entirely within your control, and it costs nothing beyond the switch itself. Matching money to its time horizon is the structural response, since the problem is most acute for cash left untouched for many years.
Some jurisdictions offer savings instruments explicitly linked to a price index, though availability, terms and tax treatment vary widely. None of this makes cash the wrong choice for short-term money, where the certainty of the balance is exactly the point. This is general information about how returns are measured and not a recommendation about where to hold your money.
Rates, thresholds and rules differ by country and change often — check current figures before acting.
Reading rates honestly
Any headline savings rate should be read alongside the current rate of price change, because the pair together is the whole story. Interest may also be taxable depending on where you live and how much you receive, which reduces the nominal figure before the comparison begins. The order of operations is therefore rate, then tax, then prices, and each step can turn a positive number into a negative one.
The arithmetic is straightforward: doing that arithmetic once a year on the largest balance is usually enough to catch an account that has quietly stopped working. Rates, allowances and tax treatment differ by country and change over time, so check the current position where you live.
The takeaway
Read every savings rate alongside what prices are doing, and after any tax. The number that matters is what the balance will buy.
The decision is rarely about picking the best option — it is about avoiding the expensive one.
Questions readers ask
Can a savings account lose money?
The balance will not fall, but its purchasing power can. If prices rise faster than the interest rate, the money buys less than it did.
Does this mean cash is a bad place for savings?
For short-term money it is usually the appropriate place, because certainty of the balance is what matters. The concern applies to money left in cash for many years.
