Looking for the best mortgage rates? A great place to start is a mortgage calculator, which lets you estimate your monthly house payment and get a better sense of how much house you can afford. Armed with that knowledge, you can narrow your home search and find the right mortgage—and the best rates.

Key Takeaways

  • A mortgage calculator lets you estimate what your monthly mortgage payments might look like.
  • Lenders may offer different types of mortgages, depending on your credit score, employment history, and debt-to-income ratio.
  • To get the best rates, you'll need a very good or an exceptional credit score. If possible, improve your credit score before you apply for a mortgage.
  • A higher down payment usually qualifies borrowers for a better interest rate because the lender will have less risk.

Buying a home may be the biggest and most important financial decision of your life, and you will likely need a mortgage to fund the purchase.

A helpful first step is to use a mortgage calculator, which estimates your monthly house payment, including principal, interest, taxes, and insurance—collectively known as "PITI." The estimate allows you to try out various scenarios to determine a realistic price range for your home search.

Mortgage Calculator

To use a mortgage calculator, you'll enter a few details about the loan, including:

  • Home price. The purchase price of the home.
  • Down payment. The cash you pay upfront to buy a home.
  • Loan term. The amount of time you have to repay the loan.
  • Loan APR (interest rate). The cost to borrow the money.
  • Property taxes. The annual tax you pay as a real property owner, levied by your city, county, or municipality.
  • Homeowners insurance. Your annual cost to insure your home and personal belongings against theft, fire, natural disasters, personal liability claims, and other covered perils.
  • HOA fees: The monthly amount you pay to your homeowners' association to help cover the costs of maintaining and improving the properties in the association. 

It's easy to change one or more variables (and it's recommended that you do so) to see how it would affect your monthly mortgage payment, mortgage interest, and the total cost of the loan.

For example, if you choose a shorter loan term, your payments will be higher, but you'll pay less interest over the life of the loan. And, of course, if you have a higher interest rate, your monthly payment will be higher—and so will the total interest.

Types of Mortgages

Depending on factors such as your credit score, employment history, and debt-to-income ratio, your lender may offer a prime rate mortgage, a subprime mortgage, or something in between, called an “Alt-A” mortgage. Here's a closer look at each:

Prime Mortgages

Prime borrowers are considered less risky by lenders. According to Experian, these borrowers typically have credit scores of at least 670, but the exact cut-off varies by lender.

Candidates for prime mortgages also have to make a considerable down payment—typically 10% to 20%—the idea being that if you’ve got skin in the game you’re less likely to default. Because borrowers with better credit scores and debt-to-income ratios tend to be lower risk, they are offered the lowest interest rates, which can save tens of thousands of dollars over the life of the loan.

Prime mortgages meet the quality standards set forth by Fannie Mae (the Federal National Mortgage Association) and Freddie Mac (the Federal Home Loan Mortgage Corporation). These are the two government-sponsored enterprises that provide a secondary market in home mortgages by purchasing loans from originating lenders.

Subprime Mortgages

Subprime mortgages are offered to borrowers who have lower credit ratings and FICO credit scores that fall in the 580-669 range, though the exact cutoff depends on the lender. Because of the increased risk to lenders, these loans carry higher interest rates.

There are several kinds of subprime mortgage structures. The most common is the adjustable-rate mortgage (ARM), which charges a fixed “teaser rate” at first, then switches to a floating rate, plus margin, for the remainder of the loan.

An example of an ARM is a 2/28 loan, which is a 30-year mortgage that has a fixed interest rate for the first two years before being adjusted. While these loans often start with a reasonable interest rate, once they switch to the higher variable rate the mortgage payments increase substantially.

Alt-A Mortgages

Alt-A mortgages (aka alternative A-paper mortgages) fall somewhere in between the prime and subprime categories. One of the defining characteristics of an Alt-A mortgage is that it is typically a low-doc or no-doc loan, meaning the lender doesn’t require much (if any) documentation to prove a borrower’s income, assets, or expenses.

This opens the door to fraudulent mortgage practices, as both lenders and borrowers can exaggerate numbers in order to secure a larger mortgage (which means more money for the lender and more house for the borrower).

In fact, after the subprime mortgage crisis of 2007-08, they became known as “liar loans” because borrowers and lenders were able to exaggerate income and/or assets to qualify the borrower for a bigger mortgage.

While Alt-A borrowers typically have credit scores of at least 700—well above the cutoff for subprime loans—these loans tend to allow relatively low down payments, higher loan-to-value ratios, and more flexibility when it comes to the borrower’s debt-to-income ratio.

These concessions enable certain borrowers to buy more house than they can reasonably afford, increasing the likelihood of default. That being said, low-doc and no-doc loans can be helpful if you actually have a good income but can’t substantiate it because you earn it sporadically (for example, if you’re self-employed).

Because Alt-As are viewed as somewhat risky (falling somewhere between prime and subprime), interest rates tend to be higher than those of prime mortgages but lower than subprime. 

Getting the Best Possible Mortgage Deal

Obviously, the higher the interest rate, the more you pay each month, and the more you ultimately pay for your home. To compare, let’s take a look at a 30-year fixed-rate mortgage for $200,000.

At the prime rate—say, 4.6% for this example—your monthly payment would be $1,025. Over the life of the loan, you would pay $169,103 in interest, so you’d actually pay back a total of $369,103.

Now assume you get the same 30-year fixed-rate mortgage for $200,000, but this time you are offered a subprime rate of 6%. Your monthly payment would be $1,199 and you’d pay a total of $231,676 in interest, bringing the total amount you pay back to $431,676. That seemingly small change in interest would cost you $62,573.

Just because a lender offers you a mortgage with an Alt-A or subprime rate doesn’t mean you wouldn’t qualify for a prime-rate mortgage with a different lender. It pays to shop around.

Lenders and mortgage brokers may be competitive, but they generally are under no obligation to offer you the best deal available. It’s well worth the effort to shop around. Taking the time to find a better interest rate can save you tens of thousands of dollars over the course of a loan.

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How To Get A Cheaper Mortgage

Tips To Find the Best Mortgage Rates

This is not the time to let somebody else do the shopping for you. As we saw just now, the terms you get can make a sizable difference in what you pay to borrow the same amount of money.

How do you avoid paying more than you need to for your mortgage? Certainly, compare the offers you get by running them through your online mortgage calculator to see what your payments and interest will be. And as you do—or even before you do—follow the steps below.

1. Improve Your Credit Score

If you’re looking for a home right now, getting your finances in great shape may be tough. So try to think ahead; maybe even postpone house-hunting until you can clean your financial house.

In general, the better your credit, the better the interest rate lenders will offer you. So, do what you can to improve your credit score by paying off credit card balances and other personal debts, to the extent you can.

Even a 20-point difference in your score could move your rate up or down more than 0.25%. On a $250,000 home, one-quarter of a point might mean an extra $12,000 or more paid in interest over the life of the loan—an extra $33 a month.

2. Save for a Down Payment

The more you can put down, the lower your mortgage payment and the less interest you’ll pay over time. A higher down payment could even mean a lower interest rate. Coming up with a 30% down payment (vs. the conventional 20%), for example, could drop your rate by more than 0.5%.

3. Use a Mortgage Calculator

A mortgage calculator estimates what your monthly payments might look like based on inputs you provide. Try different scenarios to find your optimal mortgage, with monthly payments you can comfortably afford—and total interest costs you can live with. For example, you might find that you could swing higher payments with a 15-year mortgage if you make a larger down payment.

4. Consider Interest Rates and Closing Costs

The interest rate is important, but there’s more to compare. Is there a prepayment penalty if you decide to refinance at some point? What are the total closing costs? Closing costs generally amount to 2% to 5% of the price of the home. If your home costs $150,000, expect to pay $3,000 to $7,500 in costs. That’s a big range, so it behooves you to see what a lender typically charges.

5. Consider Private Mortgage Insurance

Though they do count towards the overall cost of your mortgage, closing costs are a one-time hit. But there's another bite that keeps on biting. If your down payment is less than 20%, you’re considered a higher risk, and you may be required to carry private mortgage insurance, or PMI.

This makes you a safer bet for the lender. Trouble is, you're the one paying for it—to the tune of 0.5% to 1% of the entire loan each year. That can add thousands of dollars to what it costs to carry the loan. If you do end up having to pay for PMI, make sure it stops as soon as you've gained enough equity in your house to be eligible.

6. Make a Decision

Let’s say you get the most amazing mortgage deal. Congratulations, but move fast. The interest rate—and possibly other conditions—are locked in for a set amount of time. You have to close within the lock period or risk losing the deal. Don’t procrastinate.

The Bottom Line

Most of the work involved in getting the lowest mortgage rate happens long before you’re ready to apply. A stellar credit score and a sizable down payment are the best ways to lower your rate.

But don’t blindly trust your bank, realtor, or mortgage broker to get you the best terms. They may have a financial incentive to steer you in a certain direction. Do your own shopping, mortgage calculating, and comparing. Also, remember that just because you qualify for X amount of mortgage, there’s nothing that says you have to borrow that much.