Mortgage Calculator

How this result is built

Estimate a full monthly housing payment from price, down payment, rate, tax, insurance, PMI, and HOA dues.

A mortgage payment that only shows principal and interest is half the story. Tax, insurance, and dues leave the account on the same day the loan is paid. This calculator keeps those pieces visible so the number you plan around is the number that actually leaves your bank.

What the opening example is for

The principal-and-interest portion uses the standard fixed-rate formula. Each monthly row in the schedule rounds interest to the cent, the way servicing software does. Extra principal is applied on top of the scheduled payment and shortens the term.

The walkthrough below uses the numbers already sitting in Mortgage Calculator. Press Calculate and the headline should match this page. Then put your own figures in. The math does not run until you press the button, and Clear hides the result.

What each field is doing

The “Home price” line on Mortgage Calculator starts at $400,000.00. If the label is a rate, type the annual figure the contract uses. If it is money, type the amount that will actually move, not a rounded hope.

Mortgage Calculator treats “Down payment” as its own entry, and the form opens with $80,000.00. Leave that figure only when it matches the statement, the quote, or the plan you are testing. Press Calculate after the edit so the chart and the schedule move with it.

Before you replace it, “Interest rate” reads 7.26% on Mortgage Calculator. A round example is useful for learning the page. It is a poor substitute for the number on your own paperwork, so replace it and run the form again.

Look at “Loan term” first if you are checking Mortgage Calculator: the filled value is 30. The other fields stay put while you change this one. That is the clean way to see what this line is doing inside the result.

The “Start year” line on Mortgage Calculator starts at 2,026. If the label is a rate, type the annual figure the contract uses. If it is money, type the amount that will actually move, not a rounded hope.

Mortgage Calculator treats “Property tax” as its own entry, and the form opens with 1.20%. Percent of the home price per year. Enter a dollar amount above 30 if you already have the annual bill. Leave that figure only when it matches the statement, the quote, or the plan you are testing. Press Calculate after the edit so the chart and the schedule move with it.

The remaining fields

Before you replace it, “Home insurance per year” reads $1,500.00 on Mortgage Calculator. A round example is useful for learning the page. It is a poor substitute for the number on your own paperwork, so replace it and run the form again.

Look at “PMI per year” first if you are checking Mortgage Calculator: the filled value is $0.00. The other fields stay put while you change this one. That is the clean way to see what this line is doing inside the result.

The “HOA fee per month” line on Mortgage Calculator starts at $0.00. If the label is a rate, type the annual figure the contract uses. If it is money, type the amount that will actually move, not a rounded hope.

Mortgage Calculator treats “Other costs per year” as its own entry, and the form opens with $4,000.00. Leave that figure only when it matches the statement, the quote, or the plan you are testing. Press Calculate after the edit so the chart and the schedule move with it.

Before you replace it, “Extra monthly principal” reads $0.00 on Mortgage Calculator. A round example is useful for learning the page. It is a poor substitute for the number on your own paperwork, so replace it and run the form again.

The opening result, line by line

Press Calculate on the opening form and Monthly housing payment is $3,043.46. That is the number the rest of this section is talking about.

Principal and interest is $2,185.13 when you run the opening figures on Mortgage Calculator. That line is part of the same calculation as the headline. It is not a second balance you can spend on top of the result. Change one input and press Calculate if you want to see whether this line moves.

On this opening pass, property tax is $400.00. That line is part of the same calculation as the headline. It is not a second balance you can spend on top of the result. Change one input and press Calculate if you want to see whether this line moves.

Mortgage Calculator reports that home insurance is $125.00. That line is part of the same calculation as the headline. It is not a second balance you can spend on top of the result. Change one input and press Calculate if you want to see whether this line moves.

Other costs is $333.33 when you run the opening figures on Mortgage Calculator. That line is part of the same calculation as the headline. It is not a second balance you can spend on top of the result. Change one input and press Calculate if you want to see whether this line moves.

On this opening pass, pMI and HOA is $0.00. That line is part of the same calculation as the headline. It is not a second balance you can spend on top of the result. Change one input and press Calculate if you want to see whether this line moves.

How those lines were produced

Mortgage Calculator reports that payoff is Feb 2056. That line is part of the same calculation as the headline. It is not a second balance you can spend on top of the result. Change one input and press Calculate if you want to see whether this line moves.

Amount financed is $320,000.00 when you run the opening figures on Mortgage Calculator. That line is part of the same calculation as the headline. It is not a second balance you can spend on top of the result. Change one input and press Calculate if you want to see whether this line moves.

On this opening pass, base payment is $2,185.13. That line is part of the same calculation as the headline. It is not a second balance you can spend on top of the result. Change one input and press Calculate if you want to see whether this line moves.

The formula line on the page is M = P · r(1+r)^n / ((1+r)^n − 1). It is there so you can see the relationship the buttons are using. A schedule, when the page draws one, is that same series written row by row.

A second pass changes only “Home price”, from $400,000.00 to $440,000.00. Monthly housing payment moves from $3,043.46 to $3,356.61. Nothing else on the form was edited, so the gap between those two results is the effect of that one field on Mortgage Calculator. If the gap is tiny, this page is not very sensitive to that entry. If the gap is large, get that entry from a document before you plan around the result.

What this page will not claim

Mortgage Calculator does not know your credit score, the county’s tax bill, or what an appraiser will say. Type the price, the loan, and the escrow you were quoted. Compare the payment with the loan estimate, and treat a small rounding difference as normal.

Mortgage Calculator stops at its own formula. When the next question is different, open Amortization Calculator (A schedule that shows where each payment goes.); House Affordability Calculator (A price that fits income and the debts you already have.); Refinance Calculator (Break-even months against the interest you still pay.). Do not add those results to this one as if they were the same kind of dollar.

Check the result before you use it

Start on Mortgage Calculator by reading the labels, not the headline. The opening labels are Home price ($400,000.00), Down payment ($80,000.00), Interest rate (7.26%), Loan term (30), Start year (2,026), Property tax (1.20%), Home insurance per year ($1,500.00), PMI per year ($0.00), HOA fee per month ($0.00), Other costs per year ($4,000.00), Extra monthly principal ($0.00). If a label is not the fact you have, the result cannot turn into that fact later. The illustration on the form lands on $3,043.46. When you press Calculate and see that same figure, the button and this explanation are using one formula.

Change one field at a time. Write down the headline, edit a single line, and press Calculate again. A large jump means that line carries the result. A line that does not move is a line the formula ignores, which is a reason to confirm you opened the right page. Mortgage Calculator is built for one job: Principal, interest, tax, insurance, PMI, and HOA in one payment. The description on the page says the same thing in a sentence: Estimate a full monthly housing payment from price, down payment, rate, tax, insurance, PMI, and HOA dues.

When the paperwork disagrees

Then hold the headline next to a source outside the site. That source might be a loan estimate, an account statement, a pay stub, or the public limit named in the methodology. A few cents of difference on a long schedule is ordinary rounding. A different rate, a fee you never typed, or a tax the form does not ask for is not rounding. Correct the input. Do not average the page with the paperwork.

When the outside source still disagrees, Mortgage Calculator has reached the edge of what it will claim. It will not phone a lender, pull a county record, or apply a credit you left blank. Send the calculator name, every input, and the result you expected through the contact page if you think the formula itself is wrong. Until that is settled, read $3,043.46 as the output of the fields above and nothing else.

FAQs