Inflation is the general rise in prices over time, and it reduces what each unit of money can buy. A balance can grow on a statement and still buy less than it did a year earlier, if prices rose faster than the balance earned. That gap is the core of inflation risk, and it applies to cash, savings accounts, bonds and anything else whose value is fixed in money terms.
This guide explains how inflation is measured, shows how to calculate your real return with a worked example, and sets out what the effect means for investing. Inflation rates differ widely between countries and periods, so check the current official figures for your own country before you make any decision based on them.
What does inflation do to money?
Inflation is measured by an index of prices for a basket of goods and services, usually published by a national statistics office. The basket and its weights differ between countries, so a single headline figure hides large differences between food, rent and fuel.
Those differences often matter more to a household than the average, because the things a family buys most often may rise faster than the headline.
Inflation works like a slow charge on cash that earns nothing or less than prices rise. A balance that earns less than inflation is worth less in real terms each year, even when the number on the statement goes up. That is why the nominal balance alone is a poor measure of how well savings are doing. The question to ask is how much the money can buy after prices have moved.
Inflation can also change behaviour. Rising prices can push people to spend quickly, delay large purchases or move savings into assets they hope will keep pace. Each of these responses carries its own risk, and none removes the underlying problem that money held in a fixed form loses value when prices rise.
How do you measure your real return?
The real return is the nominal return adjusted for inflation. The precise formula is one plus the nominal return, divided by one plus inflation, minus one. A quick approximation subtracts inflation from the nominal return, which works well when both figures are small but understates the effect when they are large.
The table below uses illustrative figures, not the rates of any real country. Savings of 1,000 earn 6 percent over a year, while the price of a basket of goods rises 9 percent.
| Step | Amount | What it means |
|---|---|---|
| Starting balance | 1,000 | The savings at the start of the year |
| Price of the basket at the start | 1,000 | What the savings could buy |
| Balance after 6% interest | 1,060 | The nominal balance at the end of the year |
| Price of the same basket after 9% inflation | 1,090 | What the same goods now cost |
| Buying power of the balance (1,060 ÷ 1,090) | 0.972 | The savings buy about 97.2% of the start |
| Real return | −2.8% | The purchasing power fell, despite the interest |
The balance grew by 60, but the goods grew by 90. The real return of about minus 2.8 percent means the savings could buy less at the end of the year than at the start. A saver who looked only at the statement would see growth, while a saver who looked at prices would see a loss.
Why does inflation matter for investing?
Investing is judged against inflation because the goal is usually to preserve or grow purchasing power, not just the nominal balance. An investment that keeps pace with inflation over a long period protects the value of money, but no asset guarantees that outcome in every year. The fair comparison is the real return after costs and taxes.
Different assets respond to inflation in different ways. Cash and fixed-rate bonds are exposed when inflation rises unexpectedly, because their payments are fixed in money terms. Shares of companies that can raise their prices may hold up better, although that depends on the company and the period. Some investors also use inflation-linked instruments where they are available. Results vary by period and country, so check the evidence for any asset before you rely on it as a hedge.
The lesson is not that every investment beats inflation. It is that a holding which earns less than inflation is losing purchasing power, even when it appears to be safe. Keeping money in such a holding can be the right choice for short-term needs, but it is a costly choice for money that will not be used for many years.
What can you do about inflation?
Inflation cannot be avoided, but its effect can be managed. Common steps include keeping a cash buffer for short-term needs, reviewing savings rates against current inflation, and placing longer-term money in assets that suit its timeline. The right mix depends on income, debts and goals, and no single step fits every household.
Start by separating money you may need soon from money you will not need for years. Short-term money should be easy to reach, even if its real return is small. Longer-term money can take more risk, because it has time to recover from a bad year. Review the mix when your circumstances change, rather than reacting to every headline about prices.
How does inflation differ from one household to another?
Inflation affects households differently, because each one spends its income on a different mix of goods and services. A family that spends most of its income on food may feel a food price rise far more than the headline figure suggests. Compare the inflation rate with the costs that matter to your own budget.
Renters, homeowners and people who buy imported goods can each see a different rate. Official indexes use an average basket with set weights, which is useful for comparisons but may not match your own spending. Tracking your largest costs for a few months shows whether the headline is a fair guide to your situation, and whether your savings are keeping pace with the costs you actually pay.
Common mistakes
Judging a rate by its headline figure. A high interest rate can still be a negative real return if inflation is higher. Compare the rate with current inflation.
Ignoring inflation on long savings. A small gap each year compounds over a decade. Check the real return over the full period, not only the next statement.
Chasing an asset because it beat inflation last year. Last year's result says little about the next period. Judge the asset on its risk, cost and fit with your goals.
Checklist
- Find the current official inflation figure for your country and note the date.
- Compare each savings or investment rate with that figure, after costs and taxes.
- Calculate the real return with the exact formula for any large or long-term balance.
- Keep short-term money in a form you can reach, and accept its lower real return.
- Review longer-term holdings for their exposure to inflation.
- Check whether any inflation hedge you consider has a track record and what it costs.
- Revisit the mix once a year, or when your goals change.
Key takeaways
Inflation reduces what money can buy, so a balance that earns less than prices rise loses real value even as its nominal number grows. The real return, which adjusts the nominal return for inflation, is the right measure for savings and investments. Money needed soon should be kept safe and reachable, and longer-term money should be judged against inflation over its full horizon.
This guide is for general information, not financial advice. See the disclaimer.