How to Compare Mortgage Offers in a Spreadsheet

The lowest rate isn’t always the cheapest loan. Points, fees, and term change the real number, and the only way to see it clearly is side by side. A free mortgage comparison spreadsheet puts each offer in a column and does the math.

What to compare (not just the rate)

• Monthly payment — what you actually pay each month.
• Lifetime interest — total interest over the life of the loan; a longer term lowers the payment but can cost far more.
• Points and fees — paid upfront to lower the rate.
• Break-even on points — how many months until the monthly savings repay the upfront cost. If you’ll move or refinance before then, the points lose money.

The formulas that do the work

• Monthly payment: =PMT(rate/12, term*12, -loan_amount) — works identically in Sheets and Excel.
• Lifetime interest: =payment*term*12 - loan_amount.
• Break-even months: =upfront_points_cost / monthly_savings_vs_no_points.

Put three offers in three columns, copy the formulas across, and the cheapest total loan is obvious — often not the one with the headline rate.

Use it to negotiate

Lenders compete. A clean comparison sheet lets you take a better offer back to your preferred lender and ask them to match it. The spreadsheet pays for itself in one conversation.

These templates are operational tools, not financial advice. Always rely on each lender’s official Loan Estimate for binding figures.