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CalcTortoise

Mortgage Payoff Calculator

Find out how extra payments — monthly, once a year or a single lump sum — shorten your mortgage and cut the interest you pay.

Written by the CalcTortoise editorial team · How we work

years

Added to every monthly payment and applied to principal.

For example from a bonus or tax refund, paid with the last payment of each year.

After each extra payment

Interest saved

$111,892

Loan cleared in
24 years 5 months (5 years 7 months sooner)
Monthly payment (unchanged)
$2,528
Interest without extra payments
$510,178
Interest with extra payments
$398,286
Total extra paid
$58,400

Illustration only, not investment, tax or legal advice.

What you repay with extra payments
  • Principal$400,000 (50.1%)
  • Interest$398,286 (49.9%)
Loan balance, with and without extra paymentsWithout extra paymentsWith extra payments

Amortization schedule with extra payments

YearPaymentsExtra paidPrincipalInterestLoan balance
$30,339$2,400$6,944$25,796$393,056
$30,339$2,400$7,409$25,331$385,648
$30,339$2,400$7,905$24,834$377,743
$30,339$2,400$8,434$24,305$369,308
$30,339$2,400$8,999$23,740$360,309
$30,339$2,400$9,602$23,137$350,707
$30,339$2,400$10,245$22,494$340,462
$30,339$2,400$10,931$21,808$329,531
$30,339$2,400$11,663$21,076$317,868
$30,339$2,400$12,444$20,295$305,424
$30,339$2,400$13,278$19,462$292,146
$30,339$2,400$14,167$18,572$277,979
$30,339$2,400$15,116$17,624$262,864
$30,339$2,400$16,128$16,611$246,736
$30,339$2,400$17,208$15,531$229,528
$30,339$2,400$18,361$14,379$211,167
$30,339$2,400$19,590$13,149$191,577
$30,339$2,400$20,902$11,837$170,675
$30,339$2,400$22,302$10,437$148,373
$30,339$2,400$23,796$8,944$124,577
$30,339$2,400$25,389$7,350$99,188
$30,339$2,400$27,090$5,650$72,098
$30,339$2,400$28,904$3,835$43,194
$30,339$2,400$30,840$1,900$12,354
$11,744$800$12,354$190$0

Tap a year to see its months.

How to use this calculator

  1. Enter your loan amount, rate and term.
  2. Add an extra amount each month, each year, or as a one-time payment.
  3. Choose whether to pay off sooner or lower your payment, and compare the balance lines.

Frequently asked questions

How much does an extra payment each month save?

On a $400,000 mortgage at 6.5% over 30 years, an extra $200 a month saves $111,892 in interest and pays the loan off 5 years 7 months sooner.

What about one extra payment a year?

Making one extra full payment of $2,528 each year — the effect people aim for with biweekly payments — saves $111,979 and cuts 5 years 8 months off the loan.

Should I shorten the loan or lower my payment?

Keeping the same payment and finishing early saves the most interest. Recasting — lowering the payment after a lump sum — frees up cash each month instead: a one-time $20,000 in year 3 lowers the payment to $2,397. Not every lender offers a recast, and some charge a fee.

Do extra payments go to principal automatically?

Not always. Tell your servicer to apply the extra amount to principal, and check your statement. Some loans also carry prepayment penalties, so read your note before paying ahead.

Sources and method

The reducing-balance loan formula, run month by month with your extra payments taken off the balance.

No outside data is used. The numbers you type in are the only inputs.

Page and formula last reviewed . How we calculate · Editorial policy · Corrections and change log

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Last updated 9 October 2026. For information only — not financial advice. Check the final figures with your lender or bank.