In the general terms, banks look at the ratios in this way. These are
averages only, each bank may differ on the exact ratio's they use to qualify a
mortgage.
LTV (Loan to Value): 80% or less, good. 81% or higher and generally you must
have mortgage (PMI) Insurance.
Housing Ratio: 28% = conventional mortgage / 29% to 31% = FHA mortgage
/ 32%+ = sub prime mortgage (higher rate)
Debt Ratio: 38% = Conventional mortgage / 39% to 41% = FHA
mortgage / 42%+ sub prime mortgage (higher rate