Mortgage Calculator

Understand Your Mortgage Before You Sign

A mortgage is likely the largest financial commitment you will ever make. The difference between a 6% and a 7% interest rate on a $400,000 loan adds up to over $95,000 in total interest over 30 years. Understanding exactly how your payment is calculated and where your money goes each month is essential for making an informed decision.

This calculator takes your loan details and instantly produces your monthly payment, total interest cost, and a complete amortization schedule. No sign-ups, no email capture, no hidden upsells to lending services.

How Mortgage Amortization Works

A fixed-rate mortgage payment stays the same every month, but the split between principal and interest changes dramatically over time. In the early years, the majority of each payment covers interest charges. As the principal balance decreases, more of each payment goes toward reducing what you owe.

On a typical 30-year mortgage, you will pay more in interest than in principal for roughly the first 18-20 years. This is why additional principal payments in the early years have such a powerful effect. An extra $200 per month toward principal in the first five years can shave years off the loan and save tens of thousands in interest.

The amortization schedule this calculator generates shows this breakdown month by month. Seeing exactly when the crossover point occurs — where principal exceeds interest in each payment — gives you a concrete understanding of your loan’s trajectory.

Comparing Loan Scenarios

The most valuable use of a mortgage calculator is comparing different scenarios side by side. How much does a 15-year term save in interest versus a 30-year term? What is the impact of putting 20% down instead of 10%? If you pay an extra $300 per month, when will the loan be paid off?

These comparisons reveal information that monthly payment alone does not show. A 15-year mortgage has a higher monthly payment but often costs less than half the total interest of a 30-year loan at the same rate. A larger down payment reduces your payment and eliminates private mortgage insurance, saving money on two fronts.

What the Payment Includes

Your total monthly housing payment typically has four components, often called PITI: principal, interest, taxes, and insurance. The principal and interest portion goes to your lender. Property taxes are usually collected by the lender and held in escrow. Homeowner’s insurance protects the property and is also often escrowed. If your down payment is below 20%, private mortgage insurance adds an additional monthly cost until you reach 20% equity.

This calculator lets you include all four components so you see the true monthly cost of homeownership, not just the loan payment.