If it's more than just income level, what else determines this decision?
Any experienced BK attorney can run a Means Test on their computer. It is not only the income for the number in your family but deductions for multiple items included secured debts and priority debts. You may have children in school. You may have unusual medical expense. A real answer can not be given with the facts laid out in your question. And, running a Means Test is beyond the scope of AVVO. Look for an experienced BK lawyer.
You can't do a Chapter 13 unless your budget shows there is money available to pay into the Plan to accomplish the goals you set in your Chapter 13. For example, if you want to save your house from foreclosure, the Plan must pay off all the past due amounts owed on the property, plus trustee commissions and any legal fees. Hope this perspective helps!
You don't have to file a Chapter 7 bankruptcy if your income is below the median household income. Some people prefer filing a Chapter 7 so that they can discharge unsecured debt. Bankruptcy law offices run a means test. There are other considerations, including how much or little equity is in your primary residence, if you have a car loan, whether you have IRS debt, how much student loans you may have, etc. It's best to meet with a lawyer and get a free initial consultation.
The items I discussed above are for information and not to be relied upon. You should talk with an attorney.
Chapter 13 Bankruptcy Attorney
When you consult bankruptcy counsel, tell them that you want to keep your house. You may be able to do that in a Chapter 7 if you are current on the mortgage and you otherwise qualify under the means test and the budget (Schedules I and J) they will have you do.
The means test compares your income with the median income in your state for your family size, and deducts standard IRS expenses for your area and family size, plus secured debts and special circumstances, such as medical expenses.
If you are behind on your mortgage, ask about Chapter 13.
Again, consult a Utah bankruptcy attorney; what I am saying is not legal advice, just things to consider when you consult your attorney.