What is a mortgage calculator?
A mortgage calculator estimates the monthly cost of financing a home. Enter a home price, down payment, interest rate and mortgage term to calculate the amount borrowed and the regular principal-and-interest payment. This tool also lets you include estimated property taxes, homeowners insurance, mortgage insurance and HOA fees, so you can see a broader monthly housing-cost estimate.
The calculator runs entirely in your browser. The numbers you enter are never uploaded, stored or shared. Use any currency consistently: if the home price and costs are in dollars, the results are in dollars; if they are in another currency, the same relationship applies.
How to use the mortgage calculator
- Enter the purchase price of the home and the amount you expect to put down.
- Add the annual interest rate and the full mortgage term in years.
- Include yearly property taxes and homeowners insurance when you have estimates.
- Add monthly mortgage insurance or HOA fees only when they apply to your property or loan.
- Compare the estimated total monthly payment with the principal-and-interest figure and total interest over the loan term.
Use accurate local estimates for taxes, insurance and any association fees. You can change one input at a time to compare a lower down payment, a different interest rate or a shorter term. This makes the trade-off between the monthly payment and total interest easier to see.
How mortgage payments are calculated
The amount borrowed is the home price minus the down payment. For a fixed-rate mortgage, the calculator converts the annual rate to a monthly rate and uses the standard amortisation formula to produce an equal principal-and-interest payment across the chosen term. Early payments contain more interest because the outstanding balance is higher. Later payments apply more toward principal.
Property taxes, insurance, mortgage insurance and HOA dues are separate from the loan calculation. They may be collected with a mortgage payment, paid directly or change over time, depending on the location and loan agreement. The total monthly figure adds your entered estimates to the calculated principal-and-interest payment; it does not add closing costs, repairs, utilities or future rate changes.
Why look beyond principal and interest?
Principal and interest are important, but they are not always the full amount needed each month. Including recurring ownership costs gives a more realistic starting point for a budget. This calculator is an educational estimate, not a loan offer or affordability decision. Before applying, review the lender's written Loan Estimate and confirm local taxes, insurance, fees and loan terms.