How Much Can I Borrow in SA? Borrowing Power Explained (2026)

The single most common shock for first-time Adelaide buyers is the gap between what they think they can borrow and what the bank will actually approve. A combined household income of $180,000 sounds like it should comfortably support a $900,000 loan in any sensible interest-rate world. In 2026 it usually does not. Welcome to the post-APRA-buffer era of Australian lending.

This guide walks through every number a bank serviceability calculator uses, in the order they apply, so you can read your own borrowing power without surprises. If you want the answer right now, plug your details into the Borrowing Power Estimator; it applies the same formulas major Australian banks use.

The four numbers that determine your borrowing power

Every bank calculator does the same four-step calculation. Master these four numbers and you can predict any lender's offer within roughly $50,000.

1. Net usable income

Gross salary, minus PAYG tax, minus 2 percent Medicare, minus HECS if applicable, minus any deductible HECS, gives you net income. For couples, both partners' net incomes are added. Some lenders apply a "shading" of 80 percent to overtime, bonus, and commission income, so a $130,000 base + $20,000 bonus is usually treated as $130,000 + $16,000 = $146,000 for serviceability purposes. Rental income from investment properties is usually shaded to 75 to 80 percent to account for vacancy and management fees.

2. Reasonable living expenses

Banks compare your declared monthly expenses against the HEM benchmark (Household Expenditure Measure) for your income, location, and household size. They take the higher of the two. You cannot tell the bank you spend $400 a month on food if HEM for your bracket says $1,400, the bank will substitute HEM. HEM is roughly $3,800 per month for a couple on $180,000 with one child in Adelaide; closer to $5,200 for a couple with three children.

3. Existing debt commitments

Banks reduce serviceability by:

• Credit card limits at 3.8 percent of the limit per month, regardless of actual balance. A $10,000 limit costs roughly $380 of monthly serviceability, or about $60,000 of borrowing power.
• Personal loans at their actual repayment amount.
• Buy-now-pay-later balances at the actual repayment, treated as a recurring liability even if you intend to pay it off.
• HECS at the published 2024-25 scale (1 percent at $54,435, scaling to 10 percent above $159,663).
• Child support and maintenance at the actual amount paid.

4. The APRA-buffered loan repayment

This is where borrowing power collapses for most applicants. APRA requires banks to stress-test the loan at 3 percentage points above the contract rate. So if the bank is offering you 6.50 percent, the serviceability calculator runs the repayment at 9.50 percent. On a 30-year, $700,000 loan, the difference between 6.50 percent and 9.50 percent is roughly $1,460 more per month. That extra $17,500 per year of "phantom" repayment has to be covered by your residual income (income minus expenses minus existing debt).

The maths in one example

Take a typical first-home-buyer couple in Adelaide in 2026:

• Income: Partner A on $110,000 base, Partner B on $75,000 base. No bonus. No HECS for A, $32,000 HECS balance for B.
• Net combined income: roughly $11,750 per month after PAYG, Medicare, and B's HECS at 5 percent.
• Expenses (HEM for the bracket): $4,200 per month, no kids yet.
• Existing debt: $8,000 credit card limit (treated as $304 monthly serviceability), no personal loan.
• Residual income for loan repayments: $11,750 − $4,200 − $304 = roughly $7,246 per month.
• At 9.50 percent buffered rate, 30-year P&I, $7,246 monthly repayment supports a loan of approximately $860,000.

Now drop the buffered rate to the actual contract rate of 6.50 percent and that same $7,246 of monthly capacity supports a loan of roughly $1,140,000. The APRA buffer alone shrinks the borrowing power by 25 percent. This is the single most important number in 2026 home lending.

The levers that actually move your number

If the calculator gives you a smaller number than you need, here is the order of operations that produces the biggest gains:

Action	Typical impact on borrowing power
Close a $10,000 credit card limit	+$60,000 to $80,000
Pay off a $20,000 personal loan ($500/month)	+$80,000 to $100,000
Extend term from 25 to 30 years (if currently shorter)	+$40,000 to $60,000
Pay HECS down by $20,000 in a lump sum (if income near a threshold)	+$30,000 to $50,000, only if it drops you under a HECS threshold
Add $15,000 of overtime/bonus (if declarable consistently)	+$80,000 to $120,000
Switch to a lender with looser HEM treatment	+$30,000 to $80,000

The credit card lever is the easiest one buyers miss. A card with a $20,000 limit that you "always pay off in full" still costs you $120,000 to $150,000 of borrowing power. Cancel the cards you don't actually use before you apply.

How this maps to a real Adelaide purchase

Convert borrowing power to purchase price by working backwards through the deposit and the SA stamp duty:

• If you have a 20 percent deposit (no LMI), borrowing power of $860,000 supports a purchase price of $1,075,000. SA stamp duty on that is roughly $54,000 (RevenueSA general rate), plus LTO and conveyancer fees of about $3,500.
• If you have only 10 percent deposit (LMI required), borrowing power of $860,000 covers loan + capitalised LMI. With LMI of around $14,000, the maximum purchase becomes closer to $956,000.
• First home buyers under the SA concession (purchase under $650,000) avoid stamp duty entirely. The same borrowing power therefore covers a higher net purchase price within that bracket.

Use the True Cost Calculator to walk through every line. Match the borrowing-power output to a real purchase price including duty and fees.

Frequently asked questions

The bottom line

Borrowing power in 2026 is a function of four numbers (net income, HEM expenses, existing debt, buffered repayment), not three. The APRA buffer is doing most of the heavy lifting in shrinking what the bank will lend. Run the numbers honestly with the Borrowing Power Estimator before you fall in love with a price bracket your serviceability cannot support. The pain of finding out at the application stage is much worse than the pain of finding out before you start house-hunting.