A 650,000 house purchase contract can mortgage 420,000. A mortgage loan for a house with a value of 600,000 can be less than 420,000, and the maximum loan amount generally does not exceed 70% of the house value. 60-70% if you look for a bank yourself, and more if you look for an intermediary. It depends on what you do, the loan amount of real estate mortgage, but you may get a higher loan in the loan company, generally not less than 50 thousand, for example, 650 thousand sells 700 thousand. Between 50% and 70% of the estimated value.