This tool calculates the change in cost ofpurchasing a representative ‘basket of goodsand services’ over a period of time. For example,it may show that items costing £10 in 1955 cost $174.14 in 1990.

- Calendar Year
- Financial Year
- Quarterly

Values are denominated in dollars for periods from Marchquarter 1966 and in pounds (£) for preceding periods.For periods after 1965, use ourdecimal inflation calculator.

## Disclaimer

The results produced by the Inflation Calculator are intended as guides only and should not be regarded as'official' Reserve Bank calculations. While every effort has been made by the Bank to ensure that the data andformulae used to generate the results are accurate, the Bank accepts no liability or responsibility for the accuracyor completeness of the resulting calculations and recommends that users exercise their own care and judgment withrespect to the Inflation Calculator's use.

## Notes

### Decimalisation

The Australian currency was decimalised on 14 February 1966. Prior to decimalisation, currency was in the form ofpounds, shillings and pence. One pound was equal to 20 shillings, one shilling was equal to 12 pence, and so onepound was equal to 240 pence. Also, one guinea was equivalent to 21 shillings. For details of the precise conversionof pence to cents please refer to the Australian Bureau of Statistics 1965, 'Special Article - Decimal Currency',Year Book of the Commonwealth of Australia, cat no 1301.0.

### Data Sources

Data have been compiled from various sources to produce a single long-running series that is representative ofchanges in consumer prices in Australia over time. From the September quarter 1948 onwards, the series used is basedon the Consumer Price Index (CPI) published by the Australian Bureau of Statistics (ABS). Prior to this, a varietyof different retail price indices constructed by the Australian Statistician have been used. From 1901 until thecommencement of the CPI in 1948, the calendar and financial year data are from the ABS 1995 Year Book Australia. The quarterly data areavailable from the June quarter 1922 and are from various issues of The Labour Report. The calendar year, financial year and quarterly datafrom 1922 to 1948 are not strictly comparable. Further details are as follows:

- From 1901 to 1914, the Australian Statistician's 'A Series' Retail Price Index (RPI) is used, which provides theweighted average of the RPI for six State capital cities.
- From 1914 to June quarter 1948, the Australian Statistician's 'C Series' RPI is used. This series is equivalentin coverage to the 'A Series' RPI but broader in scope insofar as it records the prices of a wider range ofgoods. Consumption weights for this series were not updated after 1936. Also, for calendar and financial year data from the Septemberquarter 1946 to the June quarter 1948, the 'C Series' RPI is used but with its rents component replaced by thehousing group of the CPI.
- From the September quarter 1948 onwards, the ‘Quarterly’ calculator uses the CPI published by the ABS. From1949 onwards, the ‘Calendar Year’ calculator uses an annual index, where the level of the annual index is thearithmetic average of the CPI in the four quarters of the calendar year. Similarly, the ‘Financial Year’ calculator uses an annual index, where the level of the annual index is the arithmetic average of the CPI in the last two quarters of the previous calendar year and the first two quarters of the current calendar year. The CPI was introduced in 1960 andcompiled retrospectively.

For further background information see:

- Australian Bureau of Statistics 1965,'Special Article - Decimal Currency', Year Book of the Commonwealth of Australia, cat no. 1301.0.
- Australian Bureau of Statistics 1995, ‘History of Retail Price Indexes’, Year Book Australia, catno. 1301.0.
- Australian Bureau of Statistics 2011,AustralianConsumer Price Index: Concepts, Sources and Methods, cat. no. 6461.0.
- Commonwealth Bureau of Census and Statistics, The Labour Report, various issues.

### Timing of Updates

The ‘Calendar Year’ inflation calculator is updated on the day after each December quarter CPI release. The ‘Financial Year’ inflation calculator is updated on the day after each June quarter CPI release. The ‘Quarterly’ inflation calculator is updated on the day after each CPI release. The expected release dates of ABS data are shown on the ABS Release Calendar.

### Calculation

Calendar Year: A basket of goods and services valued at $100 in calendar year 2000, would in calendar year 2015 cost $150.6.

$\mathrm{I}\mathrm{n}\mathrm{f}\mathrm{l}\mathrm{a}\mathrm{t}\mathrm{i}\mathrm{o}\mathrm{n}\mathrm{b}\mathrm{e}\mathrm{t}\mathrm{w}\mathrm{e}\mathrm{e}\mathrm{n}\mathrm{c}\mathrm{a}\mathrm{l}\mathrm{e}\mathrm{n}\mathrm{d}\mathrm{a}\mathrm{r}\mathrm{y}\mathrm{e}\mathrm{a}\mathrm{r}2000\mathrm{a}\mathrm{n}\mathrm{d}2015\phantom{\rule{0ex}{0ex}}=\left(\frac{AverageofCPIlevelinMa{r}_{2015},Ju{n}_{2015},Se{p}_{2015},De{c}_{2015}}{AverageofCPIlevelinMa{r}_{2000},Ju{n}_{2000},Se{p}_{2000},De{c}_{2000}}-1\right)\times 100\%\phantom{\rule{0ex}{0ex}}=\left(\frac{\frac{1}{4}\left(106.8+107.5+108.0+108.4\right)}{\frac{1}{4}\left(69.7+70.2+72.9+73.1\right)}-1\right)\times 100\%=50.6\%$

Financial Year: A basket of goods and services valued at $100 in financial year 2000/01, would in financial year 2015/16 cost $147.1.

$\mathrm{I}\mathrm{n}\mathrm{f}\mathrm{l}\mathrm{a}\mathrm{t}\mathrm{i}\mathrm{o}\mathrm{n}\mathrm{b}\mathrm{e}\mathrm{t}\mathrm{w}\mathrm{e}\mathrm{e}\mathrm{n}\mathrm{f}\mathrm{i}\mathrm{n}\mathrm{a}\mathrm{n}\mathrm{c}\mathrm{i}\mathrm{a}\mathrm{l}\mathrm{y}\mathrm{e}\mathrm{a}\mathrm{r}2000/01\mathrm{a}\mathrm{n}\mathrm{d}2015/16\phantom{\rule{0ex}{0ex}}=\left(\frac{AverageofCPIlevelinSe{p}_{2015},De{c}_{2015},Ma{r}_{2016},Ju{n}_{2016}}{AverageofCPIlevelinSe{p}_{2000},De{c}_{2000},Ma{r}_{2001},Ju{n}_{2001}}-1\right)\times 100\%\phantom{\rule{0ex}{0ex}}=\left(\frac{\frac{1}{4}\left(108.0+108.4+108.2+108.6\right)}{\frac{1}{4}\left(72.9+73.1+73.9+74.5\right)}-1\right)\times 100\%=47.1\%$

Quarterly: A basket of goods and services valued at $100 in March 2000, would in December 2015 cost $155.5.

$\mathrm{I}\mathrm{n}\mathrm{f}\mathrm{l}\mathrm{a}\mathrm{t}\mathrm{i}\mathrm{o}\mathrm{n}\mathrm{b}\mathrm{e}\mathrm{t}\mathrm{w}\mathrm{e}\mathrm{e}\mathrm{n}\mathrm{M}\mathrm{a}\mathrm{r}\mathrm{c}\mathrm{h}2000\mathrm{a}\mathrm{n}\mathrm{d}\mathrm{D}\mathrm{e}\mathrm{c}\mathrm{e}\mathrm{m}\mathrm{b}\mathrm{e}\mathrm{r}2015\phantom{\rule{0ex}{0ex}}=\left(\frac{CPIlevelinDe{c}_{2015}}{CPIlevelinMa{r}_{2000}}-1\right)\times 100\%=\left(\frac{108.4}{69.7}-1\right)\times 100\%=55.5\%$