Mortgage Repayment Calculator
Estimate your home loan repayment by entering the property price, your deposit, the interest rate and the loan term. The calculator handles principal & interest and interest-only, and supports monthly, fortnightly and weekly schedules.
Mortgage Repayment Calculator
Enter your loan details to estimate repayments. General information only — figures are illustrative.
Indicative only. Excludes fees, LMI, stamp duty, rate changes and applicant-specific factors lenders apply. Compare a full rate table before deciding.
How to use this calculator
- Enter the property price and deposit (the calculator shows your LVR automatically).
- Set the interest rate and loan term.
- Pick monthly, fortnightly or weekly repayments.
- Review the repayment, total interest and full loan cost.
Frequently asked questions
How is a mortgage repayment calculated in Australia?
Australian lenders use the standard annuity formula: M = P × r × (1+r)^n / ((1+r)^n − 1), where P is the loan amount, r is the periodic interest rate and n is the number of periods. Our calculator implements this formula exactly — the result for a $600,000 loan at 6.00% over 30 years is $3,597.30/month, matching the federal MoneySmart calculator to the cent.
What is the difference between principal and interest and interest only?
Principal & interest (P&I) repayments include both a portion of the loan principal and the interest, so the loan amortises down to zero over the term. Interest only (IO) repayments cover only the interest, so the principal stays the same until the IO period ends and P&I repayments begin.
Should I choose monthly, fortnightly or weekly repayments?
Choosing fortnightly or weekly repayments — and not simply halving or quartering your monthly payment, but paying half a monthly amount every fortnight — effectively makes one extra month's payment per year. Over a 30-year term this typically takes 3-5 years off the loan and saves tens of thousands in interest.