A Guide to the Consumer Price Index: 17th Series

Latest release

Promotes understanding of the Consumer Price Index (CPI) as a measure of household inflation, how's it measured and how it's used

Reference period


CPI - a widely used economic indicator released quarterly

1.1 The Consumer Price Index (CPI) is an important economic indicator. It provides a general measure of changes in prices of consumer goods and services purchased by Australian households. The CPI is used for a variety of purposes, such as in the development and analysis of government economic policy, the adjustment of some government benefits and in individual contracts. Because of this, the CPI directly or indirectly affects all Australians.

1.2 CPI figures are produced by the Australian Bureau of Statistics (ABS) for each quarter (three months ending March, June, September and December) and are released on the last Wednesday of the month following the end of the reference quarter. They appear in the publication Consumer Price Index, Australia (cat. no. 6401.0). In addition, all CPI results appear on the ABS website: http://www.abs.gov.au.

CPI now comprises 17 linked series

1.3 The CPI was first compiled in 1960 with series extending back to the September quarter 1948. The CPI was preceded by five series of retail price indexes compiled by the (then) Commonwealth Bureau of Census and Statistics as far back as 1901. These series were titled the A, B, C, and D Series, and the Interim Retail Price Index respectively. The C Series Index, which began in 1921, was the principal retail price index in Australia prior to the introduction of the CPI in 1960.

1.4 The introduction of the CPI heralded a change in the approach to measuring retail price movements. Rather than compiling a set of discrete fixed-weighted indexes, the objective became to produce a series of short-term fixed-weighted indexes that were to be regularly linked together to provide a single continuous measure of price change. This strategy was adopted to ensure that, at any point in time, the weighting patterns and item coverage of the CPI were relevant to user requirements and reflected contemporary economic conditions. The CPI now comprises seventeen linked indexes. The CPI originally consisted of weights from 1948. Weights were updated in 1952 and subsequently in 1956, 1960, 1963, 1968, 1973, 1974, 1976, 1982, 1987, 1992, 1998, 2000, 2005, 2011 and 2017.

The guide

1.5 The purpose of this guide is to provide a broad overview of the CPI; how to use the CPI and how the CPI is calculated. It takes into account changes made with the introduction of the 17th series CPI in the December quarter 2017 and is suitable for general users.

1.6 For a more in-depth description of the concepts, sources and methods used to compile the CPI, refer to Consumer Price Index: Concepts, Sources and Methods (cat. no. 6461.0).

What is the CPI?

Overview of the 17th series CPI

How is the CPI used?

The CPI basket of goods and services

The relative importance of CPI items

Collecting prices for the CPI

Changes in quality

Reviews of the CPI

How does the CPI relate to me?

Example: adjusting for quality

Using the CPI

  1. Percentage change from corresponding quarter of previous year

Source: Consumer Price Index, Australia (cat. no. 6401.0)

Interpreting index numbers

Analysing the CPI

Some examples of using the CPI

Calculating the CPI

Consumer price index structure

Diagram shows consumer price index structure
The consumer price index structure has the following: All groups is the highest level of the index containing all the groups, sub-groups and expenditure classes Groups is the first level of disaggregation of the CPI. These are 11 groups in the 17th Series CPO Sub-groups are a collection of related expenditure classes. There are 33 sub-groups in the 17th series CPI. Expenditure classes are groups of similar goods or services. They are the lowest level at which indexes are published and weights are fixed. There are 87 expenditure classes in the 17th series CPI. Elementary aggregates are the basic building blocks of the CPI. Each elementary aggregate contains several prices for a particular good or service. There are approximately 800 elementary aggregates in each capital city.


Subdividing the basket

Collecting price data

Estimation of price movements for elementary aggregates

Calculating the current cost of the basket

Transactions data and multilateral methods

Previous catalogue number

This release previously used catalogue number 6440.0.

Back to top of the page