Key Highlights

  • On a 30-year principal and interest Loan of $550,000, repayments rise by about $89 a month in the illustration.
  • The example assumes hypothetical rates moving from 6.10% to 6.35%.
  • The median borrower can cover over a year of scheduled Mortgage payments from savings buffers, according to the RBA.
  • Actual lender pass-through varies, so repayments on any individual loan will differ.

A worked illustration shows how a 0.25 percentage point rise could add about $89 a month to a hypothetical $550,000 loan, and why that figure is a starting point for understanding rather than a prediction.

When the Reserve Bank of Australia lifted the cash rate target by 25 basis points to 4.85 per cent on 3 November 2026, the headline number said little about what a household might actually pay. A quarter of a percentage point sounds small. Translated into dollars on a typical-sized loan, it becomes easier to grasp.

The illustration

Take a 30-year principal and interest loan of $550,000. Assume, hypothetically, that the Interest Rate on that loan rises from 6.10 per cent to 6.35 per cent — an increase of 0.25 percentage points, matching the size of the November cash rate move.

Under those assumptions:

  • Monthly repayments at 6.10 per cent: about $3,333.
  • Monthly repayments at 6.35 per cent: about $3,422.
  • Difference: about $89 a month.

Over 12 months, that difference works out at roughly $1,068, again as an illustration on these assumed rates.

The arithmetic also shows something about proportions. An extra $89 on a repayment of about $3,333 is an increase of a little under 3 per cent in the monthly amount, even though the assumed interest rate moved by only a quarter of a percentage point.

Why "the $89 question" has no single answer

The $89 figure is useful for orientation, but several factors mean an actual borrower's experience could look quite different:

  • Pass-through varies. Lenders decide whether, when and by how much to adjust their own rates after a cash rate change. The illustration assumes the full 0.25 percentage point flows through; in practice that is not guaranteed.
  • The starting rate is an assumption. The 6.10 per cent starting point is hypothetical. A borrower on a different rate would see a different dollar change.
  • Loan structure matters. The illustration assumes a 30-year principal and interest loan. Other structures, terms or remaining balances would produce different numbers.
  • Fixed versus variable. A borrower whose rate is fixed for a period would not see an immediate change.

For comparison, the same hypothetical rate change produces about $57 more a month on a $350,000 loan and about $146 more on a $900,000 loan. The $550,000 example sits between the two.

What the RBA says about borrowers' capacity

The illustration is not an RBA estimate, but the RBA's October 2026 Financial Stability Review assessed how borrowers as a group were coping. Those findings predate the November rise.

According to the Review, the share of variable-rate owner-occupier borrowers with a cash-flow shortfall "increased a little over the first half of 2026, but remains relatively low at around 2 per cent." The median borrower can cover "over a year of scheduled mortgage payments at current interest rates" from their buffers. The Review also estimated that "less than 1 per cent of borrowers" were in negative equity.

Its overall assessment was that "Most borrowers appear well placed to manage ongoing cost pressures amid declining housing prices."

A median, by definition, describes the middle of the distribution. Some borrowers will have much larger buffers and some much smaller. An extra $89 a month is likely to feel very different depending on where a household sits.

The backdrop to the rise

The reason for the increase was inflation. The Monetary Policy Board's statement said "Inflation is now forecast to remain elevated through much of 2027", and that "the Board judged that a further tightening in financial conditions is warranted". The decision was taken by a majority of six votes to three, with the minority preferring to hold at 4.60 per cent.

The Inflation numbers come in several forms. The monthly CPI indicator showed headline annual inflation of 4.3 per cent in the September month. Over the year to the September quarter, headline CPI was 3.9 per cent and trimmed mean (underlying) inflation was 3.7 per cent. The November Statement on Monetary Policy states: "Headline inflation is expected to peak at 4.5 per cent in the December 2026 quarter".

Governor Michele Bullock acknowledged the cost to households directly: "Some pain now will prevent even worse pain down the track."

Other parts of the economy are also relevant to a household budget. The Statement noted that "housing prices have declined by more than expected", and that "The Unemployment rate rose by more than expected to average 4.6 per cent in the September quarter."

Reading the forecasts alongside the illustration

The illustration describes a single quarter-point step. It does not attempt to model what might happen to rates from here. The Statement's forecasts are built on a cash rate assumption derived from market pricing as at 28 October, which "increases by 35 basis points by mid-2027, before declining a little to stabilise at 4.8 per cent in 2028." That path is a market-based assumption used for forecasting, not a commitment or forecast by the Board.

The Board itself has said only that it "will continue to do what it considers necessary to bring inflation sustainably back to target." Its next decision is scheduled for 2.30 pm on 8 December 2026, and the October monthly CPI indicator is due on 25 November.

The bottom line

On a hypothetical $550,000, 30-year loan, an assumed rate rise from 6.10 to 6.35 per cent adds about $89 a month in this illustration, or roughly $1,068 a year. It is a useful yardstick, but not a forecast: actual changes depend on each lender's pass-through, the borrower's own rate and the structure of the loan. The RBA's October review suggested most borrowers entered this period with buffers, though that assessment came before the November decision and averages can conceal wide variation between households.