What is a good interest rate for a 30 year fixed mortgage? What is a 30-year fixed mortgage? A 30-year fixed mortgage is a loan whose interest rate stays the same for the duration of the loan. For example, on a 30-year mortgage of $300,000 with a 20% down payment and an interest rate of 3.75%, the monthly payments would be about $1,111 (not including taxes and insurance).
