Mortgage Repayment Calculator

Repayments use a standard amortisation formula: P × r / (1 − (1 + r)^−n), where P is the principal, r is the per-period interest rate, and n is the total number of periods. Each repayment goes to interest first, with the rest reducing principal.

Money in a 100% offset account reduces the principal balance that interest is calculated on each day. If your loan is $500K and your offset has $50K, you only pay interest on $450K. This can shave years off a 30-year loan.

Yes — every dollar of extra repayment goes 100% to principal, immediately reducing future interest. Even small extra repayments early in the loan can save tens of thousands over a 30-year term.

Paying more often means slightly less interest accrual between payments. The biggest effect comes from "12 monthly = 24 fortnightly" tricks — paying half the monthly amount every fortnight equals 26 fortnightly payments per year, i.e. an extra month's worth of repayments annually.

No. It calculates principal and interest only. Real loans include establishment fees, monthly account fees, LMI (if borrowing over 80% LVR), and potentially other charges. Add a buffer of $1,000-$5,000 over the loan life depending on lender.

This calculator models a principal-and-interest loan. Interest-only periods have lower repayments but no principal reduction — typically used by investors. After the IO period ends, repayments jump as principal must be paid off over the shorter remaining term.