Our mortgage comparison calculator analyzes multiple loan options side-by-side using standard amortization formulas. The calculation applies mortgage finance principles to compare monthly payments, total interest, and lifetime costs including discount points for comprehensive decision-making.

Mathematical Foundation

Mortgage comparison is based on loan amortization mathematics from financial theory. Each mortgage payment includes both principal and interest, with early payments being mostly interest and later payments mostly principal. Comparing total cost reveals the true expense difference between options—a shorter term has higher monthly payments but dramatically lower total interest. Discount points add complexity: paying upfront (1 point = 1% of loan) reduces the rate by ~0.25%, requiring break-even analysis to determine if the upfront cost justifies long-term savings.

• Lower interest rates significantly reduce total cost over 15-30 years
• Shorter loan terms have higher payments but save tens of thousands in interest
• Discount points require 5-7 years to break even typically
• Monthly payment affects affordability; total cost affects wealth
• Even 0.5% rate difference saves $30,000+ on typical mortgage
• APR comparison accounts for rate and fees together

Sources & References