Borrowing power calculator
How much could a lender let you borrow?
This estimates how a lender might assess your borrowing power using standard serviceability methods: your income after tax, living expenses, existing commitments, and an assessment rate with a buffer. It is an estimate of how a lender might assess you, not an offer or a promise. Everything runs in your browser and nothing you enter is saved or sent.
RBA cash rate: 4.35% (as at August 2026)
How the borrowing power calculator works
Lenders work out how much you can borrow by checking whether your income comfortably covers your living costs, existing debts, and the new loan repayments. This calculator follows the same standard method.
It starts with your income after tax, calculated for each applicant separately. Some income types are counted at a reduced rate, the way lenders treat them: casual income and bonuses at 80%, rental income at 80%. It then subtracts living expenses using the Household Expenditure Measure (HEM) for your household, your credit card and other loan commitments, and the repayment on the new loan.
The new loan is assessed at your interest rate plus a 3% buffer (with a floor of 5.30%), not your actual rate, so there is room if rates rise. Your borrowing power is the largest loan whose assessed repayment still leaves your income covering everything, which is where your net surplus ratio reaches 1.0.
Worked example: A single applicant earning $120,000 with no debts is assessed, at a 9.00% assessment rate over 30 years, as able to borrow roughly $641,000. The repayment shown alongside uses the actual rate you enter, not the higher assessment rate.
Assumptions
- Income tax estimated using FY2026-27 resident rates and a 2% Medicare levy.
- Tax is calculated for each applicant separately, never pooled, and the effective tax rate is applied to each income component.
- Casual income is taxed in full, then counted at 80%. Bonus and commission are counted at 80% before tax. Rental income is counted at 80% and not taxed.
- Child support, Family Tax Benefit, Carer Payment, and other non-taxable income are counted in full and not taxed.
- Living expenses use the Household Expenditure Measure (HEM) for your household type and income, with dependants capped at 3. There is no separate expenses input.
- Credit card commitments are assessed at 45.6% of your total limit each year, regardless of balance. Other loan repayments are counted at 12 times the monthly figure.
- The assessment rate is your entered rate plus a 3% buffer, with a floor of 5.30%.
- Borrowing power is the loan whose repayment, at the assessment rate, brings your net surplus ratio to 1.0. The repayment shown alongside uses your entered rate.
Frequently asked questions
How much can I borrow on a single income in Australia?
It depends on your income, living costs, and any existing debts. As a rough guide, a single person on an average full-time income with no other debts may be assessed to borrow somewhere around five to six times their income, but every lender differs. Enter your details above for an estimate.
Does child support count as income for a home loan?
Some lenders count child support and family payments, others do not, and conditions often apply (for example the age of the youngest child). This calculator counts non-taxable income like child support in full, but because policies vary so widely, this is exactly the kind of thing a broker can match to the right lender.
What is an assessment rate or serviceability buffer?
Lenders do not test your loan at your actual rate. They add a buffer (commonly 3%) to allow for rate rises, with a minimum floor rate. This calculator uses your rate plus 3%, floored at 5.30%. It is why your assessed borrowing power is lower than your actual repayments might suggest.
Why do lenders use HEM for living expenses?
The Household Expenditure Measure is a benchmark of typical household spending, scaled to your income and household size. Lenders use it as a minimum expense figure so that borrowing power is not overstated by understated expenses. A lender uses the higher of your declared expenses and HEM, but this calculator uses the HEM benchmark only, which is one reason a lender's real assessment can differ.
Is this a guarantee of how much I can borrow?
No. It is an estimate of how a lender might assess you using standard methods. Real approvals depend on your full application, credit history, employment, and each lender's specific policies, which vary significantly.
Related reading
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Important
The results from this calculator are estimates for general information and education only. They are based on the assumptions stated and the figures you enter, and do not take your personal circumstances, lender policies, or eligibility into account. They are not financial advice, credit assistance, or an offer of credit. Speak to a licensed finance broker or your lender before making decisions. Broker Codex is a directory platform and does not provide credit assistance.
Lenders each apply their own assessment rates, income policies, and expense benchmarks. Your actual borrowing power can differ significantly from this estimate in either direction.