Consumer price index: what is the trend?

The Consumer Price Index (CPI) is the main measure of inflation.

The National Institute of Statistics and Economic Studies (INSEE) confirmed that, in April 2026, the CPI increased by 1.0% over one month, just like in March and when it was already +0.6% in February.

This means that in April 2026, consumer prices rose by 2.2% year-on-year. This increase in inflation is explained, in a context of conflict in the Middle East, by the sharp acceleration in energy prices (+14.3% year-on-year in April), in particular those of petroleum products (+31.4% in April), notably diesel (+42.1% in April after +23.5% in March), gasoline (+17.8% in April after +9.9% in March) and liquid fuels (+58.9% in April after +40.9% in March).

What is the purpose of the consumer price index?

The Consumer Price Index (CPI) is calculated each month by the National Institute of Statistics and Economic Studies (INSEE) to measure the general evolution of prices of goods and services consumed by households throughout the country. It is published monthly in Official Journal.

It is an instrument for measuring inflation; it makes it possible to evaluate the average variation in the prices of products consumed by households, at constant quality.

It can be used by everyone to adapt their consumption of different goods and services and have better control over their spending and purchasing power.

Goods and services covered by the consumer price index

The CPI is calculated by observing the prices of a basket of fixed goods and services, updated each year. Several sources are used to establish the consumer price index, including:

• the collection by field investigators of the prices of different products consumed by households throughout France and in all forms of points of sale;
• a price statement on the internet;
• the collection of purchase data by supermarket retailers at the time consumers go to the checkout.

In particular, the CPI takes into account prices observed in the following sectors:

• feeding;
• tobacco;
• manufactured goods (clothing, health products, etc.);
• energy (fuel, etc.);
• services (rent, transport services, communication services, etc.).

Some goods and services are not taken into account because their price evolution is difficult to observe or because they are counted in other indices (e.g. sales of second-hand vehicles between individuals, antique furniture, antique works of art and carpets, etc.).

How is the CPI calculated?

The INSEE calculates the price evolution, between 2 periods, of the different categories of goods and services studied. The weight of each category placed in this basket of goods and services is then weighted according to its importance in the average French budget, in order to obtain an average evolution of the price of this basket.