noun

CPI

see-pee-EYE

CPI (noun) means Consumer Price Index: a measure of the average change over time in the prices paid by households for a fixed basket of goods and services, used as the main gauge of inflation. Example: “CPI rose by 3.2 per cent in the year to June.”

noun

economics Consumer Price Index: a measure of the average change over time in the prices paid by households for a fixed basket of goods and services, used as the main gauge of inflation.

"CPI rose by 3.2 per cent in the year to June."

"Pensions in some schemes are uprated in line with CPI."

marketing Cost per install: the amount an advertiser pays for each installation of an app generated by a campaign.

"The team cut its CPI from four dollars to under two."

How to Use CPI

Learner’s notes

In plain EnglishThe main number used to say how much prices have gone up.

When to use it

Economic and financial reporting; written in capitals with no full stops.

Memory tip

Say "CPI rose", not "the CPI rose by a percentage point of inflation" — the index is the measure, not the thing measured.

Trace the full origin ↓

Easily confused with

RPI PPI → PCE

Common pairings

CPI inflation headline CPI core CPI annual CPI rate

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Fill the Gap

Can you complete this real example?

_____ rose by 3.2 per cent in the year to June.

Etymology

An initialism of Consumer Price Index.

Origin: English

Synonyms

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consumer price index inflation index

Frequently Asked Questions

What is the difference between CPI and RPI?

Both track price changes for households, but they cover different baskets and use different mathematics. RPI includes some housing costs such as mortgage interest that CPI leaves out, and its formula tends to produce a higher figure. The UK no longer treats RPI as a national statistic, though some contracts still use it.

What is core CPI?

Core CPI strips out food and energy prices, which swing sharply for reasons unconnected to the wider economy. Central banks watch it because it gives a steadier picture of the underlying trend in inflation.

Does CPI measure the cost of living?

Only roughly. CPI tracks the price of a fixed basket, so it does not fully capture people substituting cheaper goods, changes in quality, or the very different spending patterns of individual households. Statistical agencies publish separate cost-of-living measures for that reason.

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Vocabulary lists that include CPI:

Words That End With I