How to calculate your monthly mortgage payments for your Houston area Home:

First, next to the space labeled "Home price," enter the price (if you're buying) In the "Down payment" section, type in the amount of your down payment (if you're buying). A down payment is the cash you pay upfront for a home. You can enter either a dollar amount or the percentage of the purchase price you're putting down.

Next, you'll see “Length of loan.” Choose the term — usually 30 years, but maybe 20, 15, or 10 — and our calculator adjusts the repayment schedule.

Finally, in the "Interest rate" box, enter the rate you expect to pay. Our calculator defaults to the current average rate, but you can adjust the percentage

As you enter these figures, a new amount for principal and interest will appear to the right. The mortgage calculator also estimates property taxes, homeowners insurance, and homeowners association fees. You can edit these amounts or even ignore them as you're shopping for a loan — those costs might be rolled into your escrow payment, but they don't affect your principal and interest as you explore your options.

Typical costs included in a mortgage payment:

• Principal: This is the amount you borrowed from the lender.

• Interest: This is what the lender charges you to lend you the money. Interest rates are expressed as an annual percentage.

• Property taxes: Local authorities assess an annual tax on your property. If you have an escrow account, you pay about one-twelfth of your annual tax bill with each monthly mortgage payment.

• Homeowners insurance: Your insurance policy can cover damage and financial losses from fire, storms, theft, a tree falling on your home, and other hazards. If you live in a flood zone, you'll have an additional policy, and if you're in Hurricane Alley or earthquake country, you might have a third insurance policy. As with property taxes, you pay one-twelfth of your annual insurance premium each month, and your lender or servicer pays the premium when it's due.

• Mortgage insurance: If your down payment is less than 20 percent of the home's purchase price, you'll probably be on the hook for mortgage insurance, which also is added to your monthly payment.