Texas Chapter 13 Calculation of Your Disposable Income is a form used in the bankruptcy process to determine how much of your income can go towards paying off debts. The calculation includes subtracting your monthly expenses from your gross income to calculate your disposable income. The disposable income will then be used to pay off creditors in a Chapter 13 repayment plan. There are two different types of Texas Chapter 13 Calculation of Your Disposable Income: the Means Test and the Allowable Expenses Test. The Means Test is a calculation of your disposable income based on your income level and the median income in your state. The Allowable Expenses Test is a calculation of your disposable income based on the IRS allowed expenses for your family size.