The Texas Attorney General's Child Support Calculator
The Texas Office of the Attorney General runs the state's child support program, and its online estimator is where most parents start. It is a legitimate tool built by the agency that publishes the underlying tax charts. This page explains what it covers, what it doesn't, and how to sanity-check a number before you rely on it.
What the OAG calculator gets right
- The guideline percentages. 20/25/30/35/40% under § 154.125(b).
- The tax conversion. Section 154.061(b) directs the Title IV-D agency to promulgate the annual tax charts used to turn gross income into net monthly income. The OAG is that agency, so its conversion is the authoritative one.
- The net-resources cap, currently $11,700 a month.
If you want the number the state's own program would start from, that is the tool to use.
Where any quick estimator runs out of road
None of this makes the OAG tool wrong. It makes it a starting point — and these are the places a real case usually departs from it.
1. The low-income multiple-family schedule. A 2021 amendment (S.B. 286) added a fourth schedule at § 154.129(b) for a parent who has other children and net resources under $1,000 a month. It is the schedule most often overlooked, and the error runs 14–30% against the lowest-income parents. A parent with $800 in net resources, one child in this case and one elsewhere owes 13.50% ($108) — not the 17.50% ($140) the ordinary multiple-family table produces.
2. Required retirement contributions. Section 154.062(d)(6) allows a deduction for nondiscretionary retirement contributions if the parent pays no Social Security tax. That covers most Texas teachers, and police and firefighters in many Texas cities. More on the TRS deduction →
3. Working backward from an order. Sometimes the useful question is the reverse one: the other side proposed $1,843 a month — what income does that assume? Dividing the proposed figure by the guideline percentage recovers the net resources behind it, and instantly shows whether your disagreement is about income or about deductions. That single step reframes a lot of negotiations. Try the reverse calculation →
4. The minimum-wage presumption. Section 154.068 presumes full-time minimum wage "in the absence of evidence" of a parent's resources. It is a rule for an empty record — not a floor that should be applied to a part-time income you can actually prove. Applied automatically, it overstates support for genuinely part-time earners.
5. Everything that isn't the percentage. Medical and dental support, retroactive support, and the § 154.123 factors a court weighs in deciding whether guideline support is unjust or inappropriate all sit outside the arithmetic.
How to check a number you have been given
- Divide the proposed support by the guideline percentage. That recovers the net resources the other side assumed.
- Compare it to the real income. If the implied figure is far above what the parent earns, the dispute is about income — deposits counted twice, a partner's money treated as the parent's, gifts characterized as salary.
- If the income is right, look at the deductions. Health and dental insurance for the child, union dues, and the retirement contribution above are the usual missing lines.
- Check which of the four schedules applies. Standard, low-income, multiple-family, or low-income multiple-family.
The honest limit on every calculator, including this one
A guideline calculation is a presumption, not a ceiling or a floor. Under § 154.123 a court may order a different amount if the evidence shows guideline support would be unjust or inappropriate, weighing the child's age and needs, each parent's ability to contribute, possession time, childcare, health expenses and more. Section 154.130 requires the court to make specific findings when it deviates.
That is why these tools are labeled estimates. They tell you where the conversation starts.