Mortgage Calculator
Use this free online Mortgage Calculator to estimate monthly home-loan repayments, total interest paid over the loan term and the full amortisation breakdown. It is useful for first-home buyers running pre-approval scenarios, refinancers comparing offers from different lenders, mortgage brokers walking clients through the maths, and investors modelling rental cash flow. Enter the property price, deposit, interest rate and term — the calculator returns principal-and-interest figures plus optional council rates and home insurance estimates so the headline number reflects what really leaves your account. Numbers run in your browser, with no sign-up. Always confirm the final figures with your lender's official Key Facts Sheet before committing.
This calculator provides general estimates only. Results may vary depending on your personal circumstances, current tax rules, fees, deductions, interest rates, and other factors. It should not be treated as financial, tax, legal, or professional advice.
How to Use This Mortgage Calculator
Setting up a mortgage estimate takes about a minute — fill in the price, deposit, rate and term.
- Enter the property price (the purchase amount, not the loan).
- Enter your deposit — the calculator works out the loan amount automatically.
- Enter the annual interest rate from your lender's offer.
- Enter the loan term in years (typically 25 or 30 in Australia).
- Optionally add property tax and insurance estimates, then click Calculate to see the full breakdown.
Example Calculation
On a $600,000 home with a $120,000 deposit (loan amount of $480,000) at 6.2% annual interest over 30 years, the calculator returns a monthly principal-and-interest repayment of around $2,940. Total interest paid across the 30-year term is approximately $578,400, bringing the total cost of the home loan to about $1.06 million on top of the original deposit.
How This Mortgage Calculator Works
A mortgage is a long-term, secured loan repaid via principal-and-interest instalments. The calculator uses the standard amortisation formula M = P × r × (1 + r)^n ÷ ((1 + r)^n − 1), where M is the monthly payment, P is the loan principal (price minus deposit), r is the monthly interest rate (annual ÷ 12 ÷ 100), and n is the total number of monthly payments (years × 12). Early payments are heavily weighted toward interest because interest is charged on the remaining balance, which is highest at the start of the loan; as the principal shrinks each month, more of every payment goes to clearing it. Total interest is the sum of all monthly interest portions, and total repayment is the monthly payment multiplied by the number of months. Real Australian home loans usually add an annual Lenders Mortgage Insurance premium when the deposit is below 20%, monthly account-keeping fees, and may switch between fixed and variable rates over the term. The calculator gives a clean baseline — confirm the final figures with your lender.
Last updated: May 2026. This calculator provides estimates only and should not be treated as financial, tax, or legal advice.
Frequently Asked Questions
What does "PITI" stand for?
Principal, Interest, Taxes, and Insurance — the four components of a typical monthly mortgage payment in the United States.
Should I take a 15-year or 30-year mortgage?
15-year mortgages have higher monthly payments but much less total interest. 30-year mortgages are easier on cash flow but cost considerably more over the life of the loan.
How much down payment should I make?
Putting down 20% in many markets avoids private mortgage insurance and reduces your monthly payment. Smaller down payments are possible but typically cost more over time.
Does the calculator include PMI or HOA fees?
No — only the four PITI components are shown. Add PMI or HOA fees manually if relevant by including them in the insurance line, or just remember to budget for them separately.
Can I prepay extra to pay off my mortgage faster?
Yes. Most U.S. mortgages allow extra principal payments without penalty. Even small additional amounts each month can shorten the loan term significantly.
This calculator provides general estimates only. Results may vary depending on your personal circumstances, current tax rules, fees, deductions, interest rates, and other factors. It should not be treated as financial, tax, legal, or professional advice.