Extra Mortgage Payment Calculator: Payoff Date & Interest Saved Spreadsheet (Excel + Google Sheets)

What happens if you pay an extra $100 or $200 a month on your mortgage? Or put your tax refund toward principal once a year? This calculator shows the new payoff date and how much interest you skip, in plain numbers.

Type in your balance, rate and years left from your mortgage statement. Then try any mix of extra payments:

• Extra principal every month

• One extra payment a year (bonus or tax refund), in the month you choose

• A one-time lump sum at the payment number you choose

What it shows you

• Your payoff date with and without the extras

• Total interest saved and months saved ("9 yrs 0 mos sooner")

• A full payment-by-payment schedule

• A year-by-year table and chart of your balance

Instant download, one .xlsx file. Works in Excel, Google Sheets (upload, then open with Google Sheets) and LibreOffice. Example values are filled in so you can see how it works. The example rate is example only, not a quote.

Educational tool only. Not a loan offer, rate quote, or financial advice.

Aaron Clark, Licensed Mortgage Loan Officer, NMLS #1770738 · www.nmlsconsumeraccess.org · Equal Housing Opportunity