Today's Mortgage Rates -- December 17, 2021: Rates Fall for Most Loans

If you're buying a home, you should check out today's average mortgage rates to see what you might pay for your loan.

On Dec. 17, 2021, average mortgage rates are down for most loans. Take a look at today's average mortgage rates for fixed and adjustable-rate mortgages so you can find out what a loan might cost you if you borrowed to buy a house today.

Data source: The Ascent's national mortgage interest rate tracking.

30-year mortgage rates

The average 30-year mortgage rate today is 3.333%, down 0.003% from yesterday's average of 3.336%. A loan at today's average rate would come with a monthly principal and interest payment of $440 per $100,000 borrowed. You'd be looking at total interest costs of $58,319 per $100,000 in mortgage debt over the life of the loan.

20-year mortgage rates

The average 20-year mortgage rate today is 3.092%, down 0.032% from yesterday's average of 3.124%. If you borrow at today's average rate, your monthly principal and interest payment would be $559 per $100,000 borrowed. During your entire loan repayment period, you'd pay total interest costs of $34,211 per $100,000 borrowed.

As you can see, this loan will save you money over time compared with the 30-year loan option. It will, however, cost more each month. If you reduce payoff time by a decade, each payment must be much higher than it would be on a loan with a longer payoff period. But this loan comes with a lower rate, and you don't pay interest for as long, so your total interest costs are much lower.

15-year mortgage rates

The average 15-year mortgage rate today is 2.578%, up 0.001% from yesterday's average of 2.577%. At today's average rate, you'd pay $670 per month in principal and interest per $100,000 borrowed. For each $100,000 you borrow at today's average rate, total interest costs would add up to $20,684.

This loan provides the most savings over time but has the highest monthly payments. Many people find a 15-year mortgage is too expensive to pay each month or too difficult to qualify for. But if you can afford the payments and want to become debt free ASAP, you may decide that this loan is right for you.

5/1 ARMs

The average 5/1 ARM rate is 2.681%, down 0.19% from yesterday's average of 2.871%. Because ARM stands for adjustable-rate mortgage, you can't count on this rate staying the same for the life of the loan. This rate is guaranteed just for the first five years. After that, the rate adjusts with a financial index and could move higher. This would leave you with both higher monthly payments and a loan that is more expensive over time.

Should I lock my mortgage rate now?

A mortgage rate lock guarantees you a certain interest rate for a specified period of time -- usually 30 days, but you may be able to secure your rate for up to 60 days. You'll generally pay a fee to lock in your mortgage rate, but that way, you're protected in case rates climb between now and when you actually close on your mortgage.

If you plan to close on your home within the next 30 days, then it pays to lock in your mortgage rate based on today's rates -- especially since they're so competitive. But if your closing is more than 30 days away, you may want to choose a floating rate lock instead for what will usually be a higher fee, but one that could save you money in the long run. A floating rate lock lets you secure a lower rate on your mortgage if rates fall prior to your closing, and while today's rates are still quite low, we don't know if rates will go up or down over the next few months. As such, it pays to:

• LOCK if closing in 7 days
• LOCK if closing in 15 days
• LOCK if closing in 30 days
• FLOAT if closing in 45 days
• FLOAT if closing in 60 days

To find out what rates are available to you, compare rates from at least three of the best mortgage lenders before locking in.