The consumer price index (CPI) is the instrument used to measure inflation. It allows the estimation of the average variation between two given periods in the prices of products consumed by households.

It is based on the observation of a fixed basket of goods updated every year. Each product has a weight in the overall index that is proportional to its weight in household expenditure.

It is published each month in the Official Journal of French Republic. The price index excluding tobacco is used to index link many private contracts, alimony, annuities and also the minimum wage (SMIC).

The index used for the SMIC is that of the "Households that belong to the lowest equivalized disposable income quintile" (Decree n° 2013-123, February 7th of 2013).

The first generation of indices dates back to 1914. Over time, the IPC's coverage has broadened, both on a geographical level and in terms of the population represented and consumption covered.

The CPI 2015 base constitutes the 8th generation of indices used. It was brought into service in January 2016.

Price collection index computation