Mortgage Amortization Calculator with Extra Payments
See your full loan schedule year by year, and how much interest and time an extra monthly payment saves.
What an amortization schedule shows
Each payment on a mortgage is split between interest and principal. Early on, most of it is interest, because the balance is large. As the balance falls, more of each payment reduces the principal. This calculator shows that split for every year and the balance that remains.
Why extra payments are powerful
Any extra money goes straight to principal. That lowers the balance that interest is charged on, so every later month costs less interest. A modest extra payment can remove years from the loan and thousands in interest.
How to use it
Enter the loan amount, rate and term, then try different extra payments. Check that your lender applies extra money to principal and does not charge a prepayment penalty.
Worked example
Last reviewed November 2026. Formulas are standard and shown in the sections above; results are estimates.
Tips and common mistakes
- Even one extra payment a year can cut years off a 30-year loan.
- Compare the interest saved with what the same money could earn invested.
- Ask your lender to apply extra payments to principal.
Learn more
Frequently asked questions
Does extra money reduce my payment?
No. The payment stays the same; the loan ends sooner.
Why is early interest so high?
Interest is charged on the balance, which is largest at the start.
Does it include tax and insurance?
No. Only principal and interest.
Is a 15-year loan better?
It costs far less interest but has a higher payment. Compare by changing the term.
Are there prepayment penalties?
Some loans have them. Check your loan terms.
Money guides for this topic
All guides →Extra Mortgage Payments: How Much Do They Save?
See how paying a little extra each month cuts years and tens of thousands in interest, and how to read an amortization schedule.
Read guide →Buying a Home or Car: The Math Before You Sign
How to work out what you can really afford for a home or car, using simple rules and real numbers.
Read guide →How Loan Interest Really Works
Understand APR, amortization and why early payments are mostly interest, with tips to pay less.
Read guide →Related calculators
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Open calculator →Results are estimates and not financial advice.