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Mortgage Refinance Calculator

See what refinancing your mortgage to today's lowest main-bank rate could save in interest and time, with an offset account working for you.

Rate check

Would refinancing save you money?

Your mortgage today against a switch to the lowest main-bank rate, with an offset account working for you.

Your mortgage

Per year
Which market rate to compare against
Lowest main-bank rate for 1 year: 4.59% (SBS Bank Special), as at 4 Oct 2026. Overtype it with a rate you have been offered.

What you pay today

Leave at $0 to use the minimum your loan requires

Working harder for you

Into the offset account each month
Average balance of your everyday account(s)
Optional - shows your LVR

Description

Compares your mortgage as it stands with a refinance to today's lowest main-bank rate, and with an optimal solution that keeps your current repayment and puts the difference, your extra, the cashback and your everyday balance into an offset account.

Assumptions

  • We assume each fixed period is re-fixed at the same rate rather than dropping to floating. Actual future rates will differ.
  • Time saved is measured against your loan's current remaining term, not against how soon you would finish at today's repayment.
  • Cashback assumes 1% of your balance less $1,500 legal costs. Lender offers vary, are often capped, and carry conditions.
  • A repayment below what your loan requires is replaced by the required minimum. Fortnightly repayments are converted to a monthly equivalent (x 26 / 12).
  • The offset account reduces the balance interest is charged on, not the balance you owe. Once it covers the loan, that month is treated as the finish line.
  • The market rate shown may not be available above 80% LVR, where lenders add a margin.

Your optimal solution

You could save up to

$422,932

and pay your mortgage off 10 yr 2 mo sooner.

Cashback and offset

Cashback (1% less $1,500 legal costs)
$5,000
Offset opening balance
$20,000
Monthly top-up to the offset
$1,254
What you actually pay each month
$4,900

Time saved is measured against your loan's current remaining term. Cashback assumes 1% of your balance less $1,500 legal costs; lender offers vary. Estimate only.

Comparison table

MeasureYour loan todayCurrent rate 6.5%Your new loanNew rate 4.59%Your optimal solutionRecommendedNew rate 4.59% + keep your current repayment + pay extra
Minimum monthly repayment$4,389$3,646$3,646
Your actual repayment$4,400$3,646$4,400
Payoff time24 yr 11 mo25 years14 yr 10 mo
Total interest amount$661,669$443,859$238,738
Interest saved (from your loan today)—$217,810$422,932
Time saved——10 yr 2 mo

Interest saved over time

"Your loan today" vs "Your optimal solution" - cumulative interest saved at each point.

1 year

$13,650

2 years

$28,002

3 years

$43,076

Whole term

$422,932

Loan balance over time

Your optimal solution shows what you owe less your offset account, so it reaches $0 the month the offset covers the loan.

Today vs your new loan vs your optimal solution

Each loan ends when it is paid off.

Your loan todayYour new loanYour optimal solution
$0$200K$400K$600K$800K202620312036204120462051