Extra Payment Calculator

How this result is built

Add a fixed extra principal amount to a loan and read the new interest and payoff time.

Extra principal is the most direct way to change a fixed loan without asking the lender for a new rate. The scheduled payment stays in place. The extra amount hits principal, the balance falls faster, and every later interest charge is smaller.

What the opening example is for

Mark the extra as principal if your lender’s form allows it. A payment that is not labeled can be held as a future installment instead of reducing the balance today.

The walkthrough below uses the numbers already sitting in Extra Payment 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 “Loan amount” line on Extra Payment Calculator starts at $18,000.00. 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.

Extra Payment Calculator treats “Interest rate” as its own entry, and the form opens with 9%. 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 remaining fields

Before you replace it, “Term” reads 5 on Extra Payment Calculator. 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.

Look at “Extra principal each month” first if you are checking Extra Payment Calculator: the filled value is $75.00. 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.

The opening result, line by line

Press Calculate on the opening form and Monthly payment is $448.65. That is the number the rest of this section is talking about.

Amount financed is $18,000.00 when you run the opening figures on Extra Payment 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 $373.65. 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.

Extra Payment Calculator reports that total interest is $3,493.81. 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

Total paid is $21,493.81 when you run the opening figures on Extra Payment 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, payoff time is 4 years. 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.

An extra $75.00 each month changes the payoff to 48 months.

A second pass changes only “Loan amount”, from $18,000.00 to $19,800.00. Monthly payment moves from $448.65 to $486.02. Nothing else on the form was edited, so the gap between those two results is the effect of that one field on Extra Payment 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

Extra Payment 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.

Extra Payment Calculator stops at its own formula. When the next question is different, open Amortization Calculator (A schedule that shows where each payment goes.); Mortgage Payoff Calculator (Lump sum plus extra monthly principal.); Loan Calculator (A fixed payment, a rate, and the interest it creates.). 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 Extra Payment Calculator by reading the labels, not the headline. The opening labels are Loan amount ($18,000.00), Interest rate (9%), Term (5), Extra principal each month ($75.00). If a label is not the fact you have, the result cannot turn into that fact later. The illustration on the form lands on $448.65. 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. Extra Payment Calculator is built for one job: One extra amount, every month, on any fixed loan. The description on the page says the same thing in a sentence: Add a fixed extra principal amount to a loan and read the new interest and payoff time.

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, Extra Payment 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 $448.65 as the output of the fields above and nothing else.

FAQs