Current Mortgage Rates -- December 30: Rates Fall for the Most Popular Loans

On Dec. 30, mortgage rates fell for three types of loans. Find out average rates today.

The month and the year are drawing to a close, but home buyers still have the opportunity to secure an unbelievably low rate on a home loan. Here's what you need to know about mortgage rates on Dec. 30 so you can decide if securing a loan is right for you.

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

30-year mortgage rates

The average 30-year mortgage rate today is 2.773%, down 0.012% from yesterday's average of 2.785%. A mortgage loan at today's average interest rate would cost you $409 per $100,000 borrowed. Over the life of the loan, your total interest costs would add up to $47,406 per $100,000 borrowed.

20-year mortgage rates

The average 20-year mortgage rate today is 2.711%, up 0.043% from yesterday's average of 2.668%. At today's average rate, you'd pay $540 per month in principal and interest per $100,000 borrowed. Total interest costs would add up to $29,658 per $100,000 borrowed over the life of the loan.

You probably noticed that while total interest costs are lower with this loan than on the 30-year alternative, your monthly payment is higher. That's because you're paying off your loan in a decade less. It'll cost you less over time since you pay interest for a shorter period, but you must pay more each month to get it paid off on schedule.

15-year mortgage rates

The average 15-year mortgage rate today is 2.188%, down 0.012% from yesterday's average of 2.200%. At today's average rate, the monthly principal and interest payment would add up to $652 per $100,000 in mortgage debt. You'd be looking at total interest costs of $17,396 per $100,000 in mortgage debt over the life of the loan.

Since you pay off a 15-year loan in an even shorter period than a 20-year loan, your monthly payment is even higher but you realize more total interest savings. You'll have to decide if the tradeoff of becoming debt free sooner is worth making a higher payment every month.

5/1 ARMs

The average 5/1 ARM rate is 3.259%, down 0.069% from yesterday's average of 3.328%. ARM stands for adjustable-rate mortgage. Many people secure ARMs if they can get a lower starting introductory rate, as this makes it worth taking the risk of rates going up. Since the interest rate on a 5/1 ARM is currently above the rate on a 30-year loan and an ARM carries the risk of payments rising, taking out this type of loan is not a good idea right now.

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.