30-Year Mortgage Calculator

What is 30-Year Mortgage Calculator?

A 30-year fixed-rate mortgage is the most widely used home loan in the United States. It spreads repayment across 360 monthly payments at a locked interest rate, offering the lowest possible monthly payment for a given loan amount. The primary advantage is cash flow flexibility — a lower required payment leaves more room in your monthly budget for savings, investments, and emergencies. The trade-off is total cost: because interest accrues on a larger remaining balance for a longer time, the total interest paid over 30 years is dramatically higher than on a shorter-term loan. On a $300,000 mortgage at 6.5%, the interest alone over 30 years totals roughly $382,000 — more than the original purchase price.

How to use

1. Enter the home purchase price or loan amount after subtracting your down payment.
2. Input the annual interest rate from your lender quote or use current average 30-year fixed rates as a benchmark.
3. The term is fixed at 30 years (360 months); confirm this matches your loan structure.
4. Click Calculate to see your estimated monthly principal-and-interest payment.
5. Review the total interest paid figure — this is the full additional cost of the loan beyond the home price.
6. Compare this result against the 15-year mortgage calculator to see the monthly payment vs. lifetime interest trade-off.

Why it matters

The 30-year mortgage's lower monthly payment is a major financial lever — it can be the difference between qualifying for a home and not, or between a tight budget and a healthy savings rate. But the long timeline has a hidden cost: because you pay interest on a larger balance for longer, the total interest bill is enormous. Many borrowers also move or refinance before the 30-year term ends — meaning they pay primarily interest during the early years of their loan, when each payment is largely interest rather than principal reduction.