Child Support Guidelines
Texas uses the percentage of obligor's income formula for calculating child support. Obligations are based on the non-custodial parent's income; they don’t factor in what the custodial parent earns. Child support is a set percentage of your net income, based on the number of children you must support. Therefore, the minimum amount would apply if you have only one child, and the percentage of your income increases with each additional child.
Your Net Income
In Texas, child support is based on what you take home each pay period, not what you earn before the government and other responsibilities take a bite. You can deduct Social Security taxes, federal and state income taxes, health insurance premiums you pay for your child, and union dues. Your minimum support obligation depends on how many of these allowable deductions you qualify for that lower your net pay.
If you were married before and you owe child support for children from that marriage, this lowers your child support percentage. If you're supporting one child from that marriage, and if you have one child from this marriage, the percentage of your income will drop.