Mortgage Calculator

What this mortgage calculator does

A mortgage is the biggest loan most people ever take, and the monthly payment is only part of what it costs. This calculator shows the payment on the loan itself (principal and interest), adds the running costs of owning the home (property tax, home insurance and any HOA or condo fees), and shows how much of your money goes to the lender in interest over the life of the loan.

How to use it

1. Enter the home price and your down payment. Use the slider or type an amount. The percentage down is shown next to it.
2. Choose the loan term, from 10 to 40 years, and enter the interest rate your lender quoted.
3. Add yearly property tax, yearly home insurance and monthly HOA fees if they apply. Leave them at zero to see the loan payment alone.
4. Pick Monthly (USA) or Semi-annual (Canada) compounding. Canadian fixed-rate mortgages compound twice a year by law, so the same headline rate gives a slightly lower payment than it would in the US.
5. Read the total monthly payment and the donut chart, which splits the payment into principal and interest, taxes, insurance and fees.

How the payment is calculated

The principal and interest payment uses the standard amortization formula: M = P × r × (1 + r)ⁿ ÷ ((1 + r)ⁿ − 1), where P is the amount borrowed (price minus down payment), r is the interest rate per month and n is the number of monthly payments. Each payment is the same size, but early payments are mostly interest and later payments are mostly principal. That is why paying extra toward principal early in the loan saves so much.

Worked example

A $450,000 home with 20% down ($90,000) leaves a $360,000 loan. At 6.5% over 30 years the principal and interest payment is about $2,275 a month, and you would pay roughly $459,000 in interest over the full term, more than the amount you borrowed. Shorten the term to 15 years and the payment rises to about $3,136 a month, but total interest drops to roughly $204,000.

Tips for a more realistic number

• Down payment size matters. In the US, putting down less than 20% usually means paying private mortgage insurance (PMI) until you build enough equity. In Canada, the minimum down payment depends on the purchase price, and smaller down payments require mortgage default insurance.
• Use your real property tax. Rates vary widely by city and county. Your listing or local assessor’s site will show the current figure.
• Budget beyond the payment. Maintenance, utilities and closing costs are not included here.
• Compare lenders on the same terms. A quarter-point difference in rate can change the total cost by thousands of dollars over 30 years.

Frequently asked questions

Is the result a quote or approval?

No. It is an estimate for planning. Your lender’s figures will depend on your credit, the exact rate, fees and local taxes.

Why is my Canadian payment lower than the US calculator shows?

Canadian fixed-rate mortgages compound semi-annually, which produces a slightly lower effective monthly rate than monthly compounding at the same quoted rate. Choose the Canada option to match.

Does a shorter term always save money?

It saves interest, but it raises the monthly payment. Choose the shortest term whose payment you can carry comfortably even if your income dips.

Are my numbers saved or sent anywhere?

No. The calculation runs in your browser and nothing you type is uploaded.