Taking out a 15-year fixed-rate mortgage — or refinancing to one — can be a smart move. First off, you'll probably get a lower interest rate. That, combined with a shorter loan term, means you'll pay significantly less interest over the life of your loan than you would with longer-term mortgages.

And a 15-year mortgage aligns much better with the length of time homeowners typically stay in one house — just eight years, according to a 2019 report from Attom Data Solutions.

There are a lot of advantages to a 15-year home loan, but it has a higher payment than mortgages with a longer term, so you want to be sure the monthly bill is going to fit within your budget. That's where a 15-year fixed mortgage payment calculator can help.

Run the numbers and see if a 15-year fixed-rate mortgage might be right for you.

What is a 15-year fixed-rate mortgage?

A 15-year fixed-rate mortgage is a home loan structured to pay off the amount owed over 15 years. A fixed rate means your interest rate will never change over the life of the loan.

How is a 15-year mortgage calculated?

There are just four required steps to calculate your 15-year mortgage payment, but the more information you provide, the more accurate the result. Here are the steps to take with the NerdWallet 15-year mortgage calculator:

  1. Provide the home's purchase price.

  2. Enter your expected down payment.

  3. Since you're considering a 15-year loan, put "15" as the loan term. You can play around with any number of loan terms to get an idea of how each would affect your monthly payment.

  4. Enter your estimated interest rate.

The results will instantly appear below the calculator inputs, in the "summary results," showing a monthly payment breakdown as well as even more payment and interest details.

One important note: If you are making a down payment of less than 20%, it's likely you'll be paying mortgage insurance. That's one variable that the 15-year calculator doesn't account for. Check out our mortgage calculator with PMI to see how private mortgage insurance might affect your payment.

To get an even better view of what mortgage interest rate you'll qualify for, click on the "Get personalized mortgage rates" green box just above the summary results. Once you nail down a custom rate, you can use it to refine the interest rate used to determine your monthly payment in the 15-year mortgage calculator.

How accurate is the estimate of your monthly mortgage payment?

The results can be enhanced with just a little more information. Your 15-year mortgage calculation will be most accurate when you supply:

  • A customized 15-year mortgage interest rate.

  • The annual property tax due on the property you are buying or refinancing. (See the "advanced inputs" section of the calculator.) For a house you're looking to buy, your real estate agent can provide you this information.

  • The annual homeowners insurance premium. Again, on a purchase, you may be able to get this from your real estate agent or your Loan Estimate.

  • Monthly homeowners association dues. Your agent likely has this, too.

When to consider a 15-year fixed mortgage

A 15-year mortgage can make sense in almost all homebuying instances, especially if you’re confident that your income won’t decrease. There really is little downside — other than the higher payment. You'll get a lower interest rate right off the bat, save a ton on interest because your loan term is half that of a 30-year loan, and gain equity in your home faster.

And that lower interest rate is locked in for the life of the loan with a fixed-rate mortgage. Your rate and monthly principal payment won't change.

What is the 15-year mortgage rate today?

NerdWallet constantly monitors mortgage rates, and you can search the rates for lenders serving your area, too. To get the most accurate quote, know your credit score and check today's 15-year mortgage rates.