How Much Can I Borrow On A Mortgage Based On My Income? This is one of the most common questions I get asked but also my most difficult to answer. In this video I will attempt to explain why it is difficult to get a straight answer to this question and show you the level of variation that you can get from one lender to another. If you are wanting to know the answer to the question how much can I borrow or how much can I borrow on the mortgage then you have come to the right place.