30-Year Fixed Rate Mortgage Calculator

What a 30-year fixed mortgage really costs

On a $340,000 loan the rate decides everything. At 5.5% the payment is about $1,931 a month and lifetime interest is roughly $355,000. At 6.5% it is $2,149 a month and $433,689 of interest. At 7.5% the payment climbs to about $2,378 and interest passes $516,000 — more than 1.5× the amount borrowed. Same house, same loan, wildly different lifetime cost. That is why the rate you lock matters more than almost any other decision in the process.

Why borrowers choose the 30-year fixed

• The lowest required payment of any mainstream term, which maximizes approval odds and monthly flexibility.
• A rate that can never move. Inflation works for you: the payment stays fixed while incomes typically rise.
• Prepay any time. Standard US mortgages have no prepayment penalty, so a 30-year loan can be paid like a 15-year loan whenever cash flow allows — the strategy behind our payoff calculator.

30-year fixed vs 15-year fixed, honestly

The 15-year on the same $340,000 at 6.0% costs about $2,869 a month — $720 more — but finishes in half the time with roughly $257,000 less interest. If the higher payment still leaves you emergency savings and retirement contributions intact, it is the cheaper loan by a landslide. If it would stretch you thin, take the 30-year and prepay in good months. Our 15 vs 30 year calculator runs both side by side with your numbers.

Who should not take a 30-year fixed?

Buyers certain to move within 5–7 years may pay less overall with an adjustable-rate mortgage, whose initial rate is lower — at the cost of adjustment risk if plans change. And if the 30-year payment only just fits your budget, the honest move is a cheaper home, not a longer bet: check the affordability calculator before you fall for a listing.