Mortgage Comparison Calculator

How this result is built

Compare payment and total interest on two mortgage offers side by side.

Offers are often waved at you as rates. The payment and the interest tell you what the rate and the term do together. A 15-year loan can win on interest and lose on monthly room. This page refuses to hide either number.

What the opening example is for

If one offer includes financed points or a different loan amount, put that amount in the loan field. Comparing two rates on different balances without saying so is how quotes get confusing.

The walkthrough below uses the numbers already sitting in Mortgage Comparison 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 “Offer A loan amount” line on Mortgage Comparison Calculator starts at $360,000.00. 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.

Mortgage Comparison Calculator treats “Offer A rate” as its own entry, and the form opens with 6.40%. 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.

Before you replace it, “Offer A term” reads 30 on Mortgage Comparison Calculator. 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

Look at “Offer B loan amount” first if you are checking Mortgage Comparison Calculator: the filled value is $360,000.00. 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 “Offer B rate” line on Mortgage Comparison Calculator starts at 6.15%. 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.

Mortgage Comparison Calculator treats “Offer B term” as its own entry, and the form opens with 15. 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.

The opening result, line by line

Press Calculate on the opening form and Interest difference (A − B) is $258,572.61. That is the number the rest of this section is talking about.

Offer A payment is $2,251.82 when you run the opening figures on Mortgage Comparison 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, offer B payment is $3,067.14. 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 Comparison Calculator reports that offer A interest is $450,656.54. 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.

Offer B interest is $192,083.93 when you run the opening figures on Mortgage Comparison 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.

A second pass changes only “Offer A loan amount”, from $360,000.00 to $396,000.00. Interest difference (A − B) moves from $258,572.61 to $303,639.99. Nothing else on the form was edited, so the gap between those two results is the effect of that one field on Mortgage Comparison 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 Comparison 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 Comparison Calculator stops at its own formula. When the next question is different, open Refinance Calculator (Break-even months against the interest you still pay.); APR Calculator (The rate that includes upfront fees.); Mortgage Calculator (Principal, interest, tax, insurance, PMI, and HOA in one payment.). 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 Comparison Calculator by reading the labels, not the headline. The opening labels are Offer A loan amount ($360,000.00), Offer A rate (6.40%), Offer A term (30), Offer B loan amount ($360,000.00), Offer B rate (6.15%), Offer B term (15). If a label is not the fact you have, the result cannot turn into that fact later. The illustration on the form lands on $258,572.61. 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 Comparison Calculator is built for one job: Two offers, one interest difference. The description on the page says the same thing in a sentence: Compare payment and total interest on two mortgage offers side by side.

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 Comparison 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 $258,572.61 as the output of the fields above and nothing else.

FAQs