By BankingMyWay.com staff

Aggressive lending practices certainly contributed heavily to the recent subprime-mortgage crisis.

But uninformed borrowers who didn't know how much home they could afford ended up putting themselves in financial jeopardy. You owe it to yourself not to make the same mistake.

Mortgage lenders calculate how much a homebuyer can afford to buy based largely on two industry standards: Your income and total debt. Your monthly mortgage payment -- including principal, interest, taxes and insurance -- shouldn't exceed 28% of your gross monthly income. And your total monthly debt payments for such things as car loans and credit card payments shouldn't exceed 36% of gross monthly income.

Even though your loan officer will crunch these numbers for you, it's a good idea to do it yourself to understand how your mortgage payments will fit in with your other monthly expenses. BankingMyWay.com's Mortgage qualifier calculator can help.

To use the calculator, enter your gross pre-tax income, the interest rate you expect to qualify for and the amount of cash you have on hand to cover the down payment and closing costs. You'll also need to enter your other monthly debt payments as well as estimates for property taxes in your area and the cost of homeowners insurance.

Let’s say you earn an annual income of $80,000 and a potential lender is offering 5.5% interest on a 30-year fixed rate mortgage with $3,000 in closing costs. (For mortgage offers near you, enter your ZIP code at BankingMyWay.com's mortgage section.) Let’s say you have saved up $25,000 and you only have $200 a month in student loans. The property tax rate in your area is 1.2% and homeowner's insurance costs 0.5% of the sales price. Based on those numbers, you’d be able to afford a $244,453 mortgage with a monthly payment of $1,867. (The mortgage payment includes $101 of Principal Mortgage Insurance because you don't have enough for a 20% down payment.)

Using the buttons at the bottom of the calculator, work backwards to figure out the variables for a specific monthly payment or home price. By playing with a range of numbers, you can figure out just how large a mortgage you're comfortable handling. That way you'll know if a mortgage lender is trying to convince you to buy more home than you can afford.

For more rate offers in your area, go to BankingMyWay.com and enter your ZIP code.

—For more ways to save, spend, invest and borrow, visit MainStreet.com.