How much will my repayments increase if interest rates rise by 1%?

On a $550,000 loan at 4.35% with 25 years remaining, a 1% rate rise increases monthly repayments by approximately $310 — an extra $3,720/year or $93,000 over the remaining term. On a $700,000 loan, the same 1% increase adds around $395/month. The exact impact depends on your loan balance, remaining term, and current rate.

What is mortgage stress and when does it occur?

Mortgage stress is broadly defined as spending more than 30–35% of gross household income on mortgage repayments. A household earning $120,000 gross ($10,000/month) enters the stress zone when repayments exceed $3,000–$3,500/month. The RBA estimates approximately 5–6% of Australian mortgage holders were in negative cash flow by mid-2026 following three consecutive rate hikes.

What should I do if I am in mortgage stress?

Contact your lender before missing a payment — hardship protections are stronger when you are proactive. Under the National Consumer Credit Protection Act, lenders must acknowledge hardship applications within 21 days and consider options like payment deferral, interest-only periods, or term extensions. Refinancing to a lower rate is also worth exploring — even in hardship, some specialist lenders will consider your application.

Free Calculator

Mortgage Stress Calculator

See exactly how a rate rise affects your monthly repayments. Model any rate scenario from +0.25% to +2.00% and understand whether your budget can absorb the change.

How much will my repayments increase if rates rise by 1%?

On a $550,000 loan at 4.35% with 25 years remaining, a 1% rate rise adds approximately $310/month — $3,720/year. On a $700,000 loan, the same increase adds around $395/month. If you are in variable rate territory, this calculator shows your exact exposure to any rate movement.

•Mortgage stress threshold: repayments exceeding 30–35% of gross household income
•APRA's 3% serviceability buffer was designed to ensure borrowers could absorb rate rises like these
•If rate rises create genuine hardship, contact your lender before missing a payment
•Refinancing to a lower rate can offset part or all of a rate increase — even mid-cycle

Explore refinancing options to reduce your rate exposure

Mortgage Stress Calculator

Rate Rise Scenarios

See exactly how a rate change affects your repayments. Choose your loan type below.

Standard repayments that reduce the loan balance each month. Models how a rate rise increases your ongoing P&I payment.

Current Loan Balance

Current Interest Rate (%)

Total Remaining Loan Term

Quick rate rise scenarios

Stressed Interest Rate (%)

Current repayment

$3,010

per month at 4.35%

At stressed rate

$3,328

per month at 5.35%

Extra per month$318

Extra per year$3,815

Total extra over 25 yrs$95,385

Moderate Impact

Review your budget — savings may be needed

Repayments rise 10.6% on a +1.00% rate move

Repayment Across Rate Scenarios

— coloured by stress level

CurrentLow impact (<8%)Moderate (8–16%)High (16–25%)Severe (>25%)

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Rate Rising? Time to Review Your Loan

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