Australian Inflation Calculator

How the Australian inflation calculator works

An inflation adjustment compares the price of the same CPI basket at two points in time. The formula is original dollars × ending CPI ÷ starting CPI. The result is the money needed in the ending quarter to match the starting amount’s purchasing power. It is not interest earned on savings.

For example, $1,000 in the March quarter of 2000 corresponds to $2,113.84 in the June quarter of 2026 using the stored ABS indices 48.40 and 102.31. The cumulative price change is 111.38%. These figures are calculated from the same observations used by the interactive tool.

Price inflation and lost purchasing power are different percentages

If prices rise from an index of 100 to 125, you need $125 to buy what $100 previously bought: a 25% price increase. But unchanged cash of $100 now buys only $80 of the original basket: a 20% purchasing-power reduction. The denominators differ, so subtracting the inflation percentage from your cash gives the wrong result.

The calculator shows both measures. The “equivalent buying power” amount answers how much money you would need later. “Value in starting-period dollars” answers what the same unchanged cash is worth in the original quarter’s prices. Deflation can reverse both results.

Quarterly CPI coverage and the September 2025 reference change

The data is ABS Table 17, original all-groups CPI for Australia, series A2325846C: a weighted average of eight capital cities. All 312 observations, September 1948 through June 2026, come from one workbook in the August 2026 release. June 2026 is the final complete quarter in that release; an August monthly observation is not a September-quarter average.

For dates before the change to decimal currency on 14 February 1966, enter a dollar-equivalent amount. This tool uses one dollar unit throughout the comparison and does not convert Australian pounds, shillings or pence. The RBA’s pre-decimal calculator provides a separate workflow for those historical denominations.

ABS re-referenced the quarterly series to September month 2025 = 100.00. This changes the index level rather than the underlying economic meaning of a price ratio. We use the historical series supplied on that basis, with no manual splice to the previous 2011–12 reference. Published rounding can cause small differences from calculations using unrounded ABS data.

Annualised inflation and comparisons with salary or savings

Annualised inflation is the compound rate that connects the two quarter indices: (ending CPI ÷ starting CPI) raised to 1 ÷ elapsed years, minus one. A five-year cumulative increase of 20% is about 3.71% a year, not 4% a year. Quarter gaps are converted to years in increments of 0.25. A same-quarter comparison has no elapsed annual rate.

To compare an earlier salary with a current offer, enter the earlier gross salary and compare the inflation-adjusted result with the proposed gross salary on the same hours. This does not calculate historical tax or the return on invested savings. Use the salary comparison tool for current after-tax job comparisons and the drawdown tool for future retirement cash flow.

CPI represents a broad spending basket. An individual household’s rent, healthcare, transport and other costs can move differently. The calculator does not estimate personal living costs, house-price growth, exchange rates or a future inflation forecast.