Mortgage Calculator: Understanding Your Home Loan
A mortgage is typically the largest financial commitment most people make in their lifetime. Understanding how mortgage payments are calculated, how interest accumulates over time, and how different terms affect total cost is essential for making informed home-buying decisions. Our Mortgage Calculator helps you model different scenarios before committing to a loan.
How Mortgage Payments are Calculated
Monthly mortgage payments are calculated using an amortization formula that factors in the loan principal, annual interest rate, and loan term. The formula ensures equal monthly payments throughout the life of the loan, but the proportion allocated to principal versus interest changes over time. In the early years, most of your payment goes toward interest. As the loan matures, more goes toward principal reduction.
The Impact of Interest Rates
Even small differences in interest rates have enormous impacts over a 30-year mortgage. On a $300,000 loan, the difference between 4% and 5% interest is approximately $170/month and over $60,000 in total interest paid over the life of the loan. This is why shopping for the best mortgage rate and considering points (prepaid interest to lower your rate) can save tens of thousands of dollars.
15-Year vs. 30-Year Mortgages
A 15-year mortgage has higher monthly payments but significantly lower total interest costs. On a $300,000 loan at 4.5%, a 30-year mortgage costs approximately $247,000 in total interest, while a 15-year mortgage costs about $114,000. That is a savings of over $133,000. However, the higher monthly payments of a 15-year mortgage may reduce your financial flexibility. Use our calculator above to compare both options and find the right balance for your budget.