Mortgage Stress Test Calculator
Test loan affordability if interest rates rise. Standard APRA-style assessment.
About this calculator
The Mortgage Stress Test Calculator on NumberCals is a free, mobile-friendly tool for anyone needing to test loan affordability if interest rates rise. standard apra-style assessment. Enter your values in the form below and the result is computed instantly — no sign-up, no installation, no waiting.
Formula used
Stress EMI = EMI at (current rate + buffer)
What you'll need
- Loan Amount (e.g. 600000)
- Current Interest Rate (%) (e.g. 6.25)
- Loan Term (years) (e.g. 30)
- Stress Buffer (%, default 3) (e.g. 3)
- Annual Gross Household Income (e.g. 150000)
- Other Monthly Debt Payments (e.g. 500)
What you'll get
- Current Monthly Payment
- Stressed Monthly Payment
- Increase per Month
- Current DTI (%)
- Stressed DTI (%)
- Assessment
Frequently Asked Questions
What DTI is considered safe? +
Lenders typically consider DTI under 35–40% comfortable. Above 50% is high-risk. APRA-supervised banks must apply a +3% interest rate buffer to all serviceability assessments.
Why test at +3%? +
It's the buffer mandated by APRA in Australia (raised from 2.5% in 2021). It protects borrowers and the financial system from rate-rise shocks.