Mortgage Comparison Calculator

The Mortgage Comparison Calculator helps you compare up to four fixed-rate loan offers side by side. See exactly how different loan amounts, interest rates, and terms affect your monthly payments, total interest, and the overall cost of each mortgage. Use the interactive charts to visualize remaining balance over time and find the deal that saves you the most money.

How to Compare Mortgage Loans

1. Select number of loans: Choose whether to compare 2, 3, or 4 mortgage offers using the dropdown.
2. Enter loan details: For each loan, enter the mortgage amount, annual interest rate (%), and loan term in years. Optionally give each loan a label (like the lender name).
3. Compare results: Click "Compare Loans" to see the full side-by-side breakdown with monthly payments, total interest, total cost, and savings potential.
4. Analyze charts: Review the bar charts for payment and cost comparison, and the line chart for remaining balance over time.

The Mortgage Payment Formula

Monthly payment for a fixed-rate mortgage is calculated using the standard amortization formula:

Where:

• M = Monthly payment
• P = Principal (loan amount)
• r = Monthly interest rate (annual rate ÷ 12 ÷ 100)
• n = Total number of payments (years × 12)

15-Year vs 30-Year Mortgage

One of the most common comparisons home buyers make. Here is how they differ:

Key Factors in Mortgage Comparison

Interest Rate

The interest rate has the largest impact on total cost. A lower rate reduces both your monthly payment and the total interest paid over the life of the loan. Always compare rates from multiple lenders.

Loan Term

Shorter terms mean higher monthly payments but dramatically lower total interest. A 15-year mortgage can save you over 50% in total interest compared to a 30-year mortgage at similar rates.

Loan Amount

The principal amount directly affects all costs. Consider how much you actually need to borrow versus what you are approved for. A larger down payment means a smaller loan and less interest paid.

Total Cost vs Monthly Payment

Do not focus only on the monthly payment. A loan with lower monthly payments may cost significantly more over its full term. This calculator shows both metrics so you can make a balanced decision.

Frequently Asked Questions

How do I compare different mortgage offers?

Enter the loan amount, annual interest rate, and loan term for each mortgage offer. The calculator computes monthly payments, total interest paid, and total cost for each loan, then highlights the best deal and shows how much you could save.

Should I choose a 15-year or 30-year mortgage?

A 15-year mortgage has higher monthly payments but much lower total interest. A 30-year mortgage has lower monthly payments but costs significantly more over the life of the loan. Use this calculator to compare exact numbers for your specific situation.

What factors affect total mortgage cost?

Three main factors affect total mortgage cost: the loan amount (principal), the interest rate, and the loan term. Even a small difference in interest rate (e.g., 0.25%) can save or cost tens of thousands of dollars over the life of a mortgage.

How is the monthly mortgage payment calculated?

Monthly payment is calculated using the standard amortization formula: M = P × r(1+r)ⁿ / ((1+r)ⁿ - 1), where P is the principal, r is the monthly interest rate (annual rate / 12 / 100), and n is the total number of monthly payments (years × 12).

Why does a lower interest rate save so much money?

Interest compounds monthly on the remaining balance. Over 30 years (360 payments), even a 0.5% rate difference on a $300,000 loan can save over $30,000 in total interest. The effect is amplified with larger loans and longer terms because interest accrues on a larger balance for more months.

Additional Resources

• Mortgage Calculator - Wikipedia
• Amortization Calculator - Wikipedia