When Texas parents share equal time with a child, courts calculate child support using the “offset” method: each parent’s guideline obligation is run separately on their own income, the smaller figure is subtracted from the larger, and the higher-earning parent pays the difference to the lower earner. The Texas Family Code doesn’t spell out a 50/50 formula, so judges have broad discretion, but the offset is the standard starting point and the number most Texas family lawyers will quote you first. How child support is calculated in Texas with 50/50 custody comes down to running the regular guideline math twice — once for each parent — and then finding the gap between the two results.
The Offset Method, Step by Step
The offset exists because the standard formula assumes one parent is the primary caregiver and the other is the payer. In equal-possession cases, both parents are housing and feeding the child half the time, so courts calculate what each parent would theoretically owe the other and net the two figures.
Suppose parents share 50/50 custody of one child. Parent A has monthly net resources of $8,000, and Parent B has $5,000.
- Parent A’s theoretical obligation: $8,000 × 20% = $1,600
- Parent B’s theoretical obligation: $5,000 × 20% = $1,000
- Offset: $1,600 − $1,000 = $600 per month from Parent A to Parent B
If both parents earn roughly the same, the offset shrinks toward zero, and a judge may decide no formal payment is needed. Even then, the court can order a small amount if one parent carries a disproportionate share of insurance, daycare, or similar costs. The offset gives you a defensible starting number; it does not bind the judge.
Figuring Each Parent’s Net Resources
The offset is only as accurate as the income figures feeding it. Texas law starts with all income — salary, overtime, bonuses, commissions, dividends, rental income, self-employment earnings — and then subtracts a specific list of items:
- Social Security taxes
- Federal income tax calculated as if the parent were single, claiming one exemption with the standard deduction
- State income tax (not applicable in Texas, but relevant for income earned in another state)
- Union dues
- Court-ordered health and dental insurance premiums for the child
What remains is the monthly net resources figure that drives the percentage calculation.1State of Texas. Texas Family Code 154.062 – Net Resources The federal tax piece uses that standardized single-filer, one-exemption formula no matter how you actually file your return or set up your W-4.
Wage earners usually document income with six months of pay stubs and a recent tax return. Self-employed parents provide gross receipts minus ordinary business expenses to establish a monthly average. The Texas Office of the Attorney General runs a free online Monthly Child Support Calculator (also called Child Support Interactive) that applies current tax tables to your numbers.2Office of the Attorney General. Monthly Child Support Calculator
The Guideline Percentages and the $11,700 Cap
Texas Family Code Chapter 154 sets support as a flat percentage of the paying parent’s monthly net resources, scaled to the number of children:
- One child: 20% of net resources
- Two children: 25%
- Three children: 30%
- Four children: 35%
- Five or more: 40%
These percentages apply automatically to the first $11,700 of monthly net resources.2Office of the Attorney General. Monthly Child Support Calculator For one child, that caps the guideline amount at $2,340 per month. When you run the offset in a 50/50 case, each parent’s theoretical obligation uses the same percentage based on how many children are covered.
Factors That Push the Number Off Pure Offset
Texas law lists 17 factors a court can weigh in deciding whether a guideline result would be “unjust or inappropriate.”3State of Texas. Texas Family Code Chapter 154 – Child Support Several hit 50/50 cases directly:
- Possession time. Equal overnights are the premise of the offset, but a judge can adjust if one parent’s time carries higher real costs, like a longer school-week commute.
- Child care. If one parent pays substantially more for daycare or after-school care to stay employed, the court can shift the offset to reflect that.
- Health insurance. The parent carrying the child’s coverage bears a cost the other doesn’t; the premium is often added to the offset or built into the final number.
- Special expenses. Private school tuition, therapy, and tutoring can raise the amount above the baseline offset.
- Travel. Significant travel to exchange the child can factor in.
- Other children. Support obligations for children from other relationships reduce available resources.
- Employer-provided benefits. A company car, housing allowance, or similar non-cash compensation can be counted as a resource.
Expect the final order to reflect these specifics rather than the raw subtraction.
When One Parent Earns Above the Cap
If a parent’s net resources exceed $11,700 per month, the guideline percentages still apply to the first $11,700. Above that line, the court leaves the percentage formula and looks at the child’s actual proven needs — tuition, medical care, extracurricular costs — and divides responsibility between the parents based on their circumstances.4State of Texas. Texas Code FAM 154.126 – Application of Guidelines to Net Resources Over Guideline Amount In a 50/50 case with a high earner, run the offset normally on the first $11,700 of each parent’s net resources; any above-guideline amount is layered on top only if the other parent documents expenses that justify it. A paying parent can never be ordered to cover more than 100% of the child’s proven needs.
When a Parent Is Voluntarily Underemployed
The offset only produces a fair result if both income numbers are honest. When a parent quits work, declines promotions, or deliberately works part-time to shrink a support obligation, Texas Family Code sections 154.066 and 154.068 let the court impute income — calculating support on what the parent could reasonably earn rather than what they actually earn. Judges look at age, education, work history, skills, and the local job market.
Imputation doesn’t apply across the board. A parent who lost a job involuntarily or has a genuine disability is assessed on actual income. An incarcerated parent is specifically excluded from being treated as voluntarily unemployed. The question is whether the lower income reflects real constraint or a strategic choice.
Making the Number Official
A handshake agreement on the offset amount has no legal force. The arrangement becomes enforceable only when a judge signs a formal order. For a new case, that means filing a Suit Affecting the Parent-Child Relationship (SAPCR) in the county where the child lives. To change an existing order, you generally file in the court that issued it, under the same cause number.5Texas Law Help. Changing a Custody, Visitation, or Child Support Order Once the order is signed, payments route through the Texas State Disbursement Unit, which creates an official record of every payment.6Texas Access. Child Support
Changing the Amount Later
Texas allows modification of a child support order in two situations:7State of Texas. Texas Code FAM 156.401 – Grounds for Modification of Child Support
- A material and substantial change in the circumstances of the child or either parent since the current order was signed — job loss, a major income increase, new medical needs, or a change in the custody schedule.
- The three-year rule: if at least three years have passed since the order was last set or modified, and recalculating under current guidelines would change the monthly amount by at least 20% or $100, either parent can request modification without showing any other change.
In 50/50 cases, the three-year rule is often the practical route. Both parents’ incomes drift over time, and a fresh run through the offset can produce a materially different number from what the old order says.
Who Claims the Child on Taxes
Child support and the dependency exemption are separate questions, but every 50/50 parent runs into this one. When the child spends an equal number of nights with each parent, the IRS awards the exemption to the parent with the higher adjusted gross income unless the other parent signs IRS Form 8332 releasing the claim.8Internal Revenue Service. Claiming a Child as a Dependent When Parents Are Divorced, Separated, or Live Apart Many 50/50 orders handle this by alternating years. Check what your order says before filing; both parents claiming the same child in the same year can trigger an IRS audit.