Mortgage Calculator

Understanding Mortgage Payments and Borrowing Cost

A mortgage is usually the largest loan you'll ever take — and the interest cost over 15 or 30 years can exceed the home price itself. Before you shop for a home, knowing your true monthly payment and lifetime borrowing cost helps you borrow responsibly and avoid stretching beyond your budget.

Your mortgage payment depends on four variables: loan amount, interest rate, term length, and whether you make extra payments. A $350,000 home with 20% down at 6.75% over 30 years produces a very different outcome than the same home with 5% down on a 15-year term. This calculator shows both the monthly payment and the total interest so you can compare scenarios.

Mortgage math uses fixed-rate amortization: early payments are mostly interest, and later payments shift toward principal. That's why extra payments in the first few years save disproportionate interest — and why refinancing or shortening your term can save tens of thousands of dollars.

Use this calculator alongside your debt-to-income ratio and budget tools. Lenders typically want housing costs below 28% of gross income and total debt below 36%. If your mortgage pushes you above those thresholds, you may struggle to qualify — or to pay down other high-APR debt.