Why Are Mortgage Payments Mostly Interest?

Posted on September 17th, 2019
Why Are Mortgage Payments Mostly Interest?

Mortgage Q&A: “Why are mortgage payments mostly interest?”

Here’s an interesting mortgage question – pun intended.

Payment Composition Over Time

  • Most homeowners take out fixed-rate mortgages
  • With monthly payments that don’t change over 30 years
  • While the mortgage payment stays the same
  • The amount that is allocated to principal and interest changes monthly

The way mortgages are set up here in the United States, each monthly payment is the same amount, assuming it’s a fully amortizing fixed-rate mortgage, which most tend to be.

This keeps housing payments more affordable (and predictable) because the balance is paid off evenly over a long period of time, such as 30 years.

However, even though the payment is fixed, the composition of the payment will change monthly until the loan term ends.

Let’s take a look at an example to illustrate:

Loan type: 30-year fixed mortgage
Loan amount: $200,000
Mortgage interest rate: 4%

In this common scenario, the monthly mortgage payment would be $954.83 for 360 months in a row. Ouch.

Each month, the borrower would need to make the same payment to the lender in order to satisfy the entire balance in 30 years.

The amount would never change, though as mentioned, the composition would. In fact, it would change every single month during the loan term.

How Much Goes Where Each Month?

amor 1

  • During the early years of a home loan
  • Most of the payment goes toward interest thanks to the large outstanding balance
  • That shifts toward principal as the loan balance shrinks over time
  • Unfortunately, most borrowers don’t keep their loans long enough to see it

As you can see from this image of the amortization schedule, the first monthly mortgage payment consists of $288.16 in principal and $666.67 in interest.

In short, the first payment on a mortgage is “mostly interest.” In fact, interest accounts for nearly 70% of the first payment. Boohoo.

In the second month, the payment is still $954.83, but the composition of the payment changes slightly. The principal portion increases to $289.12, while the interest portion drops to $665.71.

Why is this? Well, remember the first month’s principal payment of $288.16? That lowered the outstanding principal balance from $200,000 to $199,711.84.

As a result, the interest due on the second monthly payment dropped, and the principal increased, because as noted earlier, the payment amount stays constant.

Over time, this trend continues. The principal portion of the monthly mortgage payment increases while the interest portion drops.

It’s pretty minimal in the beginning because little principal is paid each month with such a large balance demanding so much interest each month.

This is the “front loaded” argument you hear about – how interest makes up the lion’s share of early payments. It’s not a gimmick, just the way math works.

Principal Surpasses Interest!

amor 2

  • It takes nearly half the loan term
  • For principal payments to exceed interest payments
  • But once this finally happens
  • Payments become very principal-heavy and the loan balance is paid down fast

In month 153, or nearly 13 years into a 30-year mortgage, the principal portion of the mortgage payment finally surpasses the interest portion.

As seen in the screenshot above, the principal portion of the monthly payment is $477.88, while the interest portion is $476.95, which still equals the original payment amount of $954.83.

Interestingly, the outstanding loan balance remains a hefty $142,608.40, or 71% of the original balance.

It’s not until month 231, or nearly 20 years into the loan term, that the outstanding balance falls below $100,000, or less than half of the original loan amount.

In other words, the bank still very much owns your home, even though you think you’re the king or queen of your castle.

However, this is where the principal really starts to get paid down, as interest finally takes a back seat.

amor 3

During the final year of the loan term, each monthly payment is more than 96% principal, with very little interest due because the outstanding balance is so low.

A small outstanding balance coupled with a low mortgage rate means associated interest will be pretty insignificant, as seen in the image above.

Assuming the loan is paid off in full, as scheduled, a borrower would pay a total of $343,739.21, of which $143,739.21 would be interest.

So it’s not mostly interest, rather mostly principal.

The Real World Scenario

  • Most homeowners sell or refinance in less than 10 years
  • So for these borrowers their payments will be mostly interest
  • But technically you pay more principal than interest
  • If the home loan is held until maturity

In reality, many homeowners don’t hold their mortgages for the full term. In fact, most are said to hold their loans for a fraction of the loan term, such as seven or eight years.

That’s right – plenty of borrowers refinance, prepay the mortgage earlier, or simply sell their home and move on to another mortgage.

So it’s kind of misleading to look at mortgages as if they’re going to last the full term. But it’s for this very reason that mortgage payments tend to be mostly interest.

Because many borrowers never get to the point where the principal actually surpasses the interest.

When borrowers do refinance, critics will argue that they’re “resetting the clock,” which refers to extending the loan term and starting the process all over again.

For example, if you paid down your existing 30-year loan for 10 years, then refinanced into another 30-year loan, you’d extend the length of your mortgage.

Same loan amount, but longer time period to pay it off, even if your mortgage rate is lower.

As a result, your balance would be paid off over 40 years, as opposed to 30. That’s 10 years from the first loan and 30 years for the refinance loan, meaning it could result in more interest paid.

Again, most borrowers don’t hold their loans that long, so again this fear is overstated and sometimes not even relevant.

However, if you are deep into a 30-year mortgage and looking to take advantage of a lower mortgage rate, consider a shorter term as well, such as a 20-year or 15-year mortgage.

That way you’ll avoid paying extra interest and stay on track to be free and clear on your home as originally intended, assuming that’s your intention.


  1. Jd March 30, 2020 at 5:44 pm -

    Basically the loan companies want their money all or most as fast as possible before you sell most likely well before the 30 years is up , win win For them ……..

  2. Nunya business May 30, 2020 at 10:39 pm -

    Yeah, seems like I agree too. Every article online does not emphasize the “turn-over” effect.

  3. Teresa Frankel October 13, 2020 at 12:50 pm -

    Pay an extra $200 in principal every month and one extra full payment a year and get rid of the debt as soon as possible😀

  4. Ron November 19, 2020 at 1:40 pm -

    I am 5 years into a 30 yr fixed at 4.25% on a 107,000 balance. I am able to pay 300 extra principal every payment. Would I benefit from refinancing to a 15 yr. 2.25% fixed loan? Yes, I plan on keeping this house and eventually making it a rental.

  5. Colin Robertson November 19, 2020 at 2:48 pm -


    You’ll need to use an amortization calculator to see what you’ve paid so far in interest and what you’d pay with the new loan via refinance, combined, versus what you’d pay if you just paid extra and kept the old loan. Also factor in closing costs.

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