United States · Federal·Updated for 2026·Figures in USD · fixed-rate loans
Mortgage Calculator
Enter the home price, your down payment and the rate to see your monthly payment, with property tax, insurance, PMI and HOA dues if you add them. You also get the total interest, when PMI can come off, and every payment in the schedule below.
Your home and loan
$
$
The cash you put down
From your Loan Estimate or lender quote
%
Monthly costs (optional)
$
From the listing or your county
$
$
Usually with less than 20% down. Ask your lender for the amount
$
Enter the price, your down payment and the rate. Your monthly payment appears here as you type — there is no button to press.
Calculating
Show the mathSee how this was worked outHide
A fixed-rate loan with level monthly payments. Interest is worked out each month on the balance and rounded to the cent, so your lender's figures can differ by a few cents.
Last reviewed October 19, 2026. The math is the standard fixed-rate formula; the PMI and escrow rules are from the Consumer Financial Protection Bureau.
A worked example
A $400,000 home with $80,000 down (20%), at 6.5% for 30 years, with $4,800 a year of property tax and $1,800 of insurance:
Part of the payment
Each month
Principal and interest on $320,000
$2,022.62
Property tax ($4,800 ÷ 12)
$400.00
Homeowners insurance ($1,800 ÷ 12)
$150.00
Total monthly payment
$2,572.62
Over 30 years the interest adds up to $408,140.64, on top of the $320,000 borrowed.
15, 20 or 30 years?
The same $320,000 loan at 6.5%, over three terms:
Term
Monthly principal and interest
Total interest
15 years
$2,787.54
$181,758.21
20 years
$2,385.83
$252,601.23
30 years
$2,022.62
$408,140.64
These use the same rate for each term to show the effect of time alone. If you are quoted different rates for different terms, enter each one in the calculator.
PMI with less than 20% down
PMI may be required on a conventional loan with less than 20% down. You can ask to cancel it once the balance reaches 80% of the home’s original value, and it generally ends automatically when the balance is scheduled to reach 78% (CFPB). With $40,000 down on a $400,000 home at 6.5% for 30 years, the $360,000 balance reaches 80% of the price at payment 95 (about 7 years 11 months in) and 78% at payment 109. Extra payments toward principal get you there sooner.
Escrow: taxes and insurance
Most lenders collect property tax and homeowners insurance with your payment and hold it in an escrow account, then pay those bills for you. The escrow part follows those bills: if your tax or insurance goes up, your total payment goes up too, even on a fixed-rate loan.
Principal and interest = loan × r ÷ (1 − (1 + r)^−n), where r is the annual rate ÷ 12 and n is the number of monthly payments. A $320,000 loan at 6.5% for 30 years is $2,022.62 a month. Property tax, insurance, PMI and HOA dues are added on top.
What does a monthly mortgage payment include?
Principal and interest, plus, for most loans, an escrow amount for property taxes and homeowners insurance that the servicer pays for you. PMI and HOA dues are added when they apply.
When do I have to pay PMI?
A conventional lender may require private mortgage insurance when your down payment is less than 20% of the price. It protects the lender, not you, and is usually added to the monthly payment.
When does PMI go away?
You can ask your servicer to cancel it once the balance reaches 80% of the home's original value, and it generally ends automatically when the balance is scheduled to reach 78%, if your payments are current. With 10% down on a $400,000 home at 6.5%, that is about payment 95 and payment 109.
Should I choose a 15-year or a 30-year mortgage?
A shorter term has a higher payment but far less interest. On $320,000 at 6.5%, 30 years costs $2,022.62 a month and $408,140.64 in interest; 15 years costs $2,787.54 a month and $181,758.21. If a lender quotes you a different rate for the shorter term, enter it in the calculator to compare.
Does this include closing costs?
No. Closing costs are paid at the start and are listed on your Loan Estimate and Closing Disclosure. This calculator covers what you pay every month.
What interest rate should I use?
The calculators take the interest rate you enter. KnownSum does not publish or predict mortgage rates; use the rate on your Loan Estimate or your lender's quote.
