Loan Payoff Calculator With Additional Payments

An additional payment goes straight to the balance, so the loan ends sooner and charges less interest. On a $25,000 loan at 9% with 60 months left, an extra $130 a month ends it 1 year 2 months sooner and saves $1,523 of interest.

Enter your own loan, then read the tables to see how the size of the extra and the kind of loan change the result.

Loan payoff calculator with additional payments

Payoff with no extra: 5 years, $6,138 of interest.

Payoff with the extra: 4 years 1 month, $4,894 of interest.

You save $1,244 of interest and finish 0 years 11 months sooner.

The extra as a share of the payment

The loan is $25,000 at 9% with 60 months left, a payment of $518.96. With no extra it ends in 5 years and costs $6,138 in interest.

Extra a monthShare of paymentPaid off inSooner byInterest saved
$5210%4 years 6 months0 years 6 months$718
$13025%3 years 10 months1 year 2 months$1,523
$25950%3 years 1 month1 year 11 months$2,425
$519100%2 years 3 months2 years 9 months$3,460

The same $100 on three loans

A fixed extra of $100 a month does more on a longer, larger loan.

LoanPaid off inSooner byInterest saved
$10,000 at 6%, 3 years2 years 3 months0 years 9 months$250
$25,000 at 9%, 5 years4 years 1 month0 years 11 months$1,244
$50,000 at 7%, 10 years8 years 1 month1 year 11 months$4,186

How the calculator works

  1. The required payment comes from the standard loan formula for your balance, rate and months left.
  2. Each month, interest = balance x rate / 12. The payment plus the extra, minus that interest, comes off the balance.
  3. The count stops when the balance reaches zero. Interest is the sum of every month's interest.

Ask your lender to apply the extra amount to the balance, not to the next payment.

The CFPB says a prepayment penalty is a fee that some lenders charge if you pay off all or part of your mortgage early. Other loans set their own terms, so read your agreement for an early payoff fee.

For a car loan with a one-time payment see the car loan early payoff calculator; for a mortgage see the extra payments mortgage payoff calculator.

Frequently asked questions

Which loans does this work for?

Any fixed-rate loan that charges interest on the remaining balance each month: a personal, car, student or home loan. It does not fit a loan with precomputed interest, or a credit card, where the payment changes.

Is a bigger extra always worth it?

It saves more, but the gain per dollar shrinks. On the example loan an extra $52 a month saves $718 and an extra $519 saves $3,460: ten times the extra, about 4.8 times the saving.

Do additional payments lower the monthly payment?

No. The required payment stays the same and the loan ends sooner, unless the lender reamortizes the loan. Ask whether the extra money goes to principal and what happens to the next due date.

Should I pay extra every month or once a year?

A dollar saves more interest the earlier it reaches the balance. The same total paid in monthly pieces lands earlier than one payment at the end of the year, so monthly saves slightly more.

How do I find the payoff date in a spreadsheet?

Use NPER(rate/12, -(payment + extra), balance). It returns the number of months left.

Sources

Every figure on this page comes from the pages below. Checked 2026-11-08. Rules change, so confirm with your own servicer.

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