How this calculator works
It follows the same broad steps lenders use, so the result is usually lower than a simple online calculator:
- Income. Base salary counts in full. Overtime, bonuses, commission, rental and other income count at 80%, a common lender discount.
- Tax. It uses the 2026–27 resident tax rates, the Low Income Tax Offset and the Medicare levy.
- HECS-HELP. Compulsory repayments use the ATO's 2026–27 rates, which only apply to income above $69,528. Source: ATO
- Living expenses. It uses the higher of your figure and a modelled household expense benchmark.
- Credit cards. Each card counts as a repayment of 3.8% of its limit every month, whatever the balance.
- The buffer. Repayments are tested at your rate plus 3%, the minimum buffer APRA expects banks to use.
Why a lender's figure may be different
Every lender applies its own policy on top of these basics. They differ on how much overtime and rental income they count, which expense benchmark they use, how they treat other debts, and their own debt-to-income limits. For the same person, the difference can be tens of thousands of dollars. What lenders assess differently explains where they vary.
How to borrow more
- Close credit cards you don't use, or lower the limits.
- Pay off small debts, such as a car loan near its end or buy now pay later balances.
- Keep your spending steady for a few months before you apply.
- Choose a lender whose policy suits your income type.
Our borrowing capacity article explains each of these in more detail.
Tax, HECS-HELP and buffer settings are current as at October 2026. Results are estimates only.