A principal-and-interest loan uses level repayments covering the interest on the outstanding balance plus some principal. Early on most of each repayment is interest; over time the balance falls and you owe nothing at the end of the term. A longer term lowers the repayment but increases total interest; a higher rate raises both.

This tool converts the annual rate to the chosen frequency. Choosing fortnightly repayments — paying half the monthly amount every two weeks — results in 26 payments a year (the equivalent of 13 monthly payments), which shortens the loan and reduces interest. Lenders also assess serviceability at a higher buffer rate, so the loan you qualify for may differ from what today's rate alone suggests.