Essentials Mortgage Refinance Calculator Spreadsheet Template for Google Sheets & Excel

Both mortgages, described the same way. The current one takes the balance outstanding, the rate you are on, the years left and the month the new schedule would start. The refinance takes its rate, its term and the closing costs. Both payments are calculated rather than typed, which means the comparison rests on the same arithmetic on both sides. Underneath, the figures that follow from those two: the monthly saving, the total interest each loan carries, the interest saved between them, the break-even point on the closing costs, the total cost of each loan with those costs included, and the net saving after them. Where the new payment is not lower, the break-even figure does not invent a negative period. Worth reading the two terms together. A refinance quoted over thirty years against a mortgage with twenty-five left is a longer loan as well as a cheaper one, and the total cost lines are where that shows up - which is why the sheet reports both the monthly figure and the whole-term one rather than only the first.

Three hundred and sixty months, both loans side by side. Each row carries the date, the payment and remaining balance on the current mortgage, and the payment, interest and remaining balance on the refinanced one. Every figure is calculated from the Refinance Setup sheet, so changing a rate redraws the whole schedule. The balance columns are the ones worth watching. Two loans with the same balance today and different terms diverge slowly and then obviously, and the month where the refinanced balance stops falling faster is the month the longer term starts costing something.

Six figures and a chart. The top row carries the monthly saving, the break-even point in months and the interest saved across the term; the row beneath carries the current payment, the new payment and the net saving once closing costs are taken off. A detail table sets the two loans against each other line by line - rate, term in months, payment, total interest, closing costs and total cost - with each column headed by its own term, so a 25-year remainder is never silently compared with a 30-year quote. The chart plots the two balances falling across the full term. It is the view that answers what the monthly figure cannot, which is where the two loans actually stand against each other in five or ten years.