Basically, if you are over, then you are a chapter 13. If you are under, then you are a chapter 7.
Now remember that these numbers can be adjusted by child support payments (received or made), larger mortgages, huge tax debt, etc. It is a gross overgeneralization to say that if you are over that figure then you MUST be a chapter 13, but this is the baseline we start with. That being said, here are the current figures for Salt Lake County that we use on our Form 22C (6 month average of current monthly income and disposable income):
Single: $52,021
Married: $58,595
Married with 1 child: $66,552
Married with 2 children: $72,274
Married with 3 children: $80,374
Married with 4 children: $88,474
Married with 5 children: $96,574
Married with 6 children: $104,674
Married with 7 children: $112,774
Married with 8 children: $120,874
Married with 9 children: $128,974
Married with 10 children: $137,074