Nominal Value vs Real Value: What's the Difference?

Economic data can be expressed in either nominal or real terms, and the difference is not just technical. A rise in a monetary figure does not automatically mean purchasing power has grown, or that more goods and services have actually been produced. Nominal value reflects prices at the time they were recorded, with no adjustment for the general price level. Real value corrects for that, adjusting the figure for inflation so it reflects what it is genuinely worth. 

What is nominal value?

Nominal value is the monetary value of a good or service based on the prices at the time it is measured. It does not take changes in the overall price level into account. Current prices are commonly used to measure the market value of the final goods and services produced by a country. Consequently, nominal GDP can increase due to higher production or increased prices or a combination of both.

What is real value?

Real value, or inflation-adjusted value, is a monetary value adjusted for changes in the general price level. That adjustment is what makes it possible to compare figures from different time periods in the first place, since a pound in 2015 and a pound today don't represent the same purchasing power. Economists rely on a relevant price index to work out the real value of goods and services during periods of inflation and deflation. 

The Consumer Price Index (CPI) can be used to adjust nominal wages for changes in consumer prices. Real GDP, on the other hand, is calculated using price measures (the GDP deflator) that reflect changes in the prices of the economy's overall output rather than simply applying the CPI, allowing for more accurate comparisons of the volume of goods and services produced by an economy over time. Real GDP per capita (in real terms) is also useful for comparing economic output across countries and over time. It is not, though, the only measure of economic well-being worth looking at. The nominal-real distinction matters to economists for a specific reason: it lets them separate a rise in prices from an actual rise in output, two things that a raw GDP figure on its own cannot tell apart. 

Worked example: a £10,000 salary in 2015

Suppose an employee earns an annual salary of £10,000 in both 2015 and 2026. The nominal amount stays the same; however, as a result of inflation, the purchasing power of this amount declines as the cost of goods increases. According to the Office for National Statistics (ONS), the UK CPI index was 100 in 2015 and 142.5 in June 2026, meaning that the general price level was approximately 42.5% higher in June 2026 than in 2015.

£10,000 ÷ (142.5 ÷ 100) ≈ £7,018

Therefore, £10,000 in 2026 has the same purchasing power as £7,018 in 2015. This shows that there has been roughly a 30% decrease in purchasing power over this period. To maintain the same purchasing power as a £10,000 salary in 2015, an employee would need to earn around £14,250 in 2026. 

Why the distinction matters

The difference between real and nominal values matters most when you're comparing figures across time.

• Wages: if inflation runs at 4% while wages go up 3%, real wages have actually fallen, and prices moved faster than pay did.
• Interest rates: real interest rate ≈ nominal interest rate − inflation rate.
• GDP: when nominal GDP rises, economists have to work out how much of that is higher output and how much is just higher prices.

Understanding the difference between nominal and real values helps facilitate comparisons of economic data across periods, particularly for wages, interest rates and GDP.