• Certain allowed expenses, in amounts set by the IRS. Generally, you cannot subtract what you actually spend for things like transportation, food, clothing, and so on; instead, you have to use the limits the IRS imposes, which may be lower than the cost of living in your area.
• Monthly payments you will have to make on secured and priority debts. Secured debts are those for which the creditor is entitled to seize property if you don't pay (such as a mortgage or car loan); priority debts are obligations that the law deems to be so important that they are entitled to jump to the head of the repayment line. Typical priority debts include child support, alimony, tax debts, and wages owed to employees.

If your total monthly disposable income after subtracting these amounts is less than $100, you pass the means test, and will be allowed to file for Chapter 7. If your total remaining monthly disposable income is more than $166.66, you have flunked the means test, and will be prohibited from using Chapter 7.

So what about those in the middle? They have to do some more math. If your remaining monthly disposable income is between $100 and $166.66, you must figure out whether what you have left over is enough to pay more than 25% of your unsecured, nonpriority debts (such as credit card bills, student loans, medical bills, and so on) over a five-year period. If so, you flunk the means test, and Chapter 7 won't be available to you. If not, you pass the means test, and Chapter 7 remains an option.