Lesson 3 of 7
When you invest, your capital is at risk.
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You have probably noticed that the same weekly shop costs more than it did a year or two ago. The same goes for petrol, your electricity bill, that coffee on the way to work. The numbers on your receipts have shifted, but the money in your account may not have grown to match.
This gap is inflation at work. Inflation does not appear as a fee or a charge or show up as a loss on a statement. But it changes what your money can do. For a saver or early investor, this matters because cash that sits still can lose real value if prices rise faster than interest earned (and after any tax on this). The question is not just how much money you have, but how much it will buy when you need it.
Inflation is the general rate at which prices rise over a given period, usually expressed as an annual percentage. It is not about one item becoming more expensive. Inflation is about the broad direction of prices across the economy and affects what is often termed the cost of living.
Inflation is measured using official price indices that track a basket of everyday goods and services, such as food, fuel, clothing, housing and transport. A price index is a single measure that summarises how the average price of that basket changes over time.
The flip side of inflation is purchasing power: when inflation goes up, purchasing power goes down. As prices rise, each pound you hold buys a smaller slice of that basket. Your pound has not changed in nominal terms, but its real value has.
Nominal value is the number on the note or in your account. Real value is what that number actually buys you. This difference is the key to understanding how inflation works in practice.
Inflation is a rate, not a price level. It tells you how fast prices are changing, usually shown as an annual percentage.
Purchasing power falls as inflation rises. The same amount of money buys fewer goods and services over time.
Inflation is measured across a broad basket. Official indices, such as the Consumer Prices Index, track a wide range of items to reflect what households typically spend on.
The causes are varied. Demand outpacing supply, rising costs for materials or labour, geopolitical conflict and shifts in currency value can all feed through to higher prices. No single factor explains every change.
Inflation is not the same as the overall price level. Prices can be high and stable, or low and rising. Inflation describes the movement, not the destination.
Imagine you have £1,000 at the start of the year. Over the next 12 months, prices across the economy rise by 4%.
At the start, $1,000 could buy a certain amount of goods and services. By the end of the year, those same goods and services cost £1,040. Your balance still reads £1,000 but it now covers less than it did before.
Now consider two scenarios. In the first, your money sits in an account earning 1% interest. After a year, you have £1,010, but prices have risen by 4%. In real terms, you have lost ground. In the second, your money earns 5%. You finish with £1,050, and your purchasing power has edged £10 or 1% ahead of inflation.
The nominal amount matters less than what it can buy. That is the lens inflation gives you.
These rates are examples only; actual rates change and tax on interest (where applicable) can affect your real return.
One practical way to think about inflation is to compare the return you are earning on cash against the rate at which prices are rising. If the return is lower than inflation, your real value is falling even while your balance grows.
This is not a reason to act on impulse. It is a way to understand the numbers you are working with. For example, you can look at the interest rate you are earning and compare it with published inflation measures (such as those produced by the Office for National Statistics). As seen in the graph below, the rate of inflation in the UK has varied considerably over the past six years.
That comparison helps you judge whether your money is holding, losing or gaining ground in real terms. It does not tell you what to do next or which account or investment to choose, but it helps you frame the decision and understand the information available to you.
Thinking one item equals inflation. A single price rising, whether for petrol or lettuce, is not inflation on its own. Inflation is the average movement across a broad basket of goods and services.*
Confusing inflation with the price level. Inflation is the rate of change, not the total. Prices can be high and steady, or low and climbing.
Treating cash as risk-free. While cash doesn’t usually fluctuate day to day like investments, and eligible UK deposits are protected by the FSCS up to certain limits, inflation can still erode what it buys over time.
Assuming higher wages cancel out inflation. Wages can lag behind price rises, and they do not always move in step. Even when pay increases, it may not match the erosion in purchasing power.
*Price indices are averages; your personal experience of inflation may be higher or lower depending on what you buy.
Inflation is the rate at which prices rise across the economy over time.
It reduces purchasing power, so the same money buys less as time passes.
It is measured across a broad basket of goods and services, not by any single price.
Cash left idle can lose real value even when its nominal amount is unchanged.
Comparing your return against the inflation rate shows whether your money is keeping pace.
Inflation is the rate at which prices for goods and services rise over time. When inflation occurs, each pound buys slightly less than it did before, eroding the purchasing power of money.
Inflation works by raising the average price of a broad basket of goods and services. As those prices climb, the purchasing power of your money falls. A pound that bought a full basket last year may cover less of it this year.
Inflation can be driven by several factors. Demand rising faster than supply, higher costs for materials or labour and changes in currency value can all push prices up. Most episodes involve a mix of causes rather than a single trigger.
It depends on what your savings earn. If your interest rate is lower than the inflation rate, your money loses real value even as the balance grows. If it earns more than inflation (after any tax on interest), your purchasing power increases.
