How To Calculate a Mortgage Payment

Under "Home price," enter the price (if you're buying) or the current value (if you're refinancing). EDU also has a refinancing calculator.

Under "Down payment," enter the amount of your down payment (if you’re buying) or the amount of equity you have (if refinancing). A down payment is the cash you pay upfront for a home, and home equity is the value of the home, minus what you owe.

On desktop, under "Interest rate" (to the right), enter the rate. Under "Loan term," click the plus and minus signs to adjust the length of the mortgage in years.

On mobile devices, tap "Refine Results" to find the field to enter the rate and use the plus and minus signs to select the "Loan term."

You may enter your own figures for property taxes, homeowners insurance and homeowners association fees, if you don’t wish to use EDU’s estimates. Edit these figures by clicking on the amount currently displayed.

The mortgage calculator lets you click "Compare common loan types" to view a comparison of different loan terms. Click "Amortization" to see how the principal balance, principal paid (equity) and total interest paid change year by year. On mobile devices, scroll down to see "Amortization."

Formula For Calculating a Mortgage Payment

The mortgage payment calculation looks like this: M = P [ i(1 + i)^n ] / [ (1 + i)^n – 1]

The variables are as follows:

  • M = monthly mortgage payment
  • P = the principal amount
  • i = your monthly interest rate. Your lender likely lists interest rates as an annual figure, so you’ll need to divide by 12, for each month of the year. So, if your rate is 5%, then the monthly rate will look like this: 0.05/12 = 0.004167.
  • n = the number of payments over the life of the loan. If you take out a 30-year fixed rate mortgage, this means: n = 30 years x 12 months per year, or 360 payments.


View More Calculators

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