The average interest rate on a 30-year fixed mortgage is now 6.76%, compared to last week's 6.85%.For those seeking a faster payoff, the average rate on a 15-year fixed mortgage has decreased to 5.74%.Today's 30-year mortgage cost is approximately $649 per month, while a 15-year mortgage costs around $830 per month.Mortgage rates are influenced by economic factors such as U.S. Treasury bond yields and the Federal Reserve's decisions.