Mortgage Overpayment Calculator

Find out exactly when you could be mortgage-free, and how much interest you'd save, by overpaying a little each month or paying in a lump sum. Type in your mortgage once and every number works itself out. Made for UK homeowners. It follows how UK mortgages really work: your fixed or tracker rate, then a new rate when the deal ends (with the payment recalculated), "shorter term" or "lower payments" after you overpay, and a year-by-year check against the usual 10% overpayment allowance so you don't pay an early repayment charge by accident. If your fix ends soon, the Compare Deals tab shows which remortgage deal is really cheapest once fees and cashback are counted. A US edition ($, refinance comparison with points and closing costs) is included. Works in Google Sheets AND Excel. WHAT'S INSIDE (6 tabs) - Dashboard: mortgage-free date with and without overpaying, time saved, interest saved, monthly payment, total interest, when your deal ends, a what-if table (what if I paid 50, 100, 200 or 500 more a month?) and a balance chart - My Mortgage: balance, years left, interest rate, deal end date, rate after the deal, regular monthly overpayment (from any month) and up to 30 one-off lump sums - Schedule: every month for up to 40 years, side by side without and with overpayments: rate, payment, interest, overpayment and balance - By Year: year-end balances, interest paid each year, overpayments made and an allowance check (within limit or over) - Compare Deals: up to 4 remortgage deals with rate, deal length, product fee (paid or added to the loan), other fees and cashback. Shows the monthly payment, interest, balance at the end of the deal and true cost, ranked cheapest first - Start Here: simple instructions WHAT YOU GET - 2 versions: £ (UK) and $ (US) - Quick Start guide (PDF) No logins, no apps and no adverts: your numbers stay in your own file. HOW IT WORKS - Download the files from your Etsy Purchases page - Google Sheets: upload the .xlsx to Google Drive, open it, then File > Save as Google Sheets - Excel: just open it (Excel 2010 or later, Windows or Mac, or Excel for the web) - Type in the cream cells. Everything else updates on its own - A Quick Start PDF walks you through setup in 5 minutes GOOD TO KNOW - Plain formulas only: no macros, no add-ins, no subscriptions - Formula cells are locked so you can't break them by accident (no password, so you can unlock and customise) - Apple Numbers and LibreOffice aren't officially supported PLEASE NOTE - This is a DIGITAL download. Nothing physical will be shipped. - Personal use only. Please don't share or resell the files. This is a calculator for planning, not financial or mortgage advice. Results are estimates and can differ slightly from your lender's figures. Always check your lender's overpayment rules and charges before overpaying. Designed by Thexton Labs. Artwork and layouts were created with our own code, with the help of AI tools.