Lenders use a ratio called "debt-to-income" to decide the most you can pay monthly after your other recurring debts have been paid.
About the Qualifying Ratio
Typically, conventional mortgages need a qualifying ratio of 28/36. An FHA mortgage will usually allow for a higher debt load, reflected in a higher (29/41) ratio.
The first number is the percentage of your gross monthly income that can go toward housing. This ratio is figured on your total payment, including homeowners' insurance, HOA dues, PMI - everything that makes up the payment.
The second number is what percent of your gross income every month which can be applied to housing expenses and recurring debt together. For purposes of this ratio, debt includes payments on credit cards, auto/boat payments, child support, and the like.
Some Example Data:
28/36 (Conventional)
- Gross monthly income of $6,500 x .28 = $1,820 can be applied to housing
- Gross monthly income of $6,500 x .36 = $2,340 can be applied to recurring debt plus housing expenses
With a 29/41 (FHA) Qualifying Ratio
- Gross monthly income of $6,500 x .29 = $1,885 can be applied to housing
- Gross monthly income of $6,500 x .41 = $2,665 can be applied to recurring debt plus housing expenses
If you want to run your own numbers, please use this Mortgage Qualification Calculator.