What Will My Income Level and Credit Score Need to Be to Be Approved for a Mortgage of $300,000?

I am trying to figure out if I can simply be turned down for a mortgage and"how much"house I will be approved for. What is considered an acceptable income-mortgage payment ratio? And what is the minimum credit score I need to have before I start applying?

Suggestion:

Your income should be around 1/3 of your mortgage…so 100K. Minimum credit score for an FHA loan is currently 620.