Mortgage Offset Calculator: Check Your Bank Is Charging You the Right Interest
A 2026 ASIC review found banks paid out more than $55 million after failing to correctly set up or link customers' mortgage offset accounts, and warned that more hidden errors are likely still out there. This free offset account calculator lets you check the numbers yourself in under a minute. Enter your loan balance, offset balance and interest rate to see exactly how much interest you should be charged, with every step of the maths shown.
Your loan details
$
$
% p.a.
Use 28–31 depending on the month you're checking.
Result
Net balance
$0
Daily rate
0%
Daily interest charge
$0
Interest for the month
$0