Last updated August 21, 2026.
For most parents, child support is the first concrete number in a divorce or custody case — and the one that affects the household budget every single month. The good news: Oklahoma doesn’t leave the amount to guesswork. Support is set by statutory guidelines, and the guideline amount is presumed correct in every case (43 O.S. § 118).
If you’re facing a child support question in the Oklahoma City metro — whether in Edmond, Norman, Moore, Midwest City, or Yukon — Peterson Law Center can help you get the number right. Here’s how the calculation actually works, in plain English.
The Short Answer: Both Parents’ Incomes, One Shared Obligation
Oklahoma uses an “income shares” model. The idea is that a child should receive the same share of parental income they would have received if the parents lived together. In practice:
- Each parent’s monthly gross income is determined.
- The two incomes are combined, and a statutory schedule sets the total base support obligation for that combined income and number of children. The schedule is built to cover the basics — housing, food, transportation, basic public-school expenses, clothing, and entertainment (43 O.S. § 118).
- That base obligation is divided between the parents in proportion to their adjusted gross incomes (43 O.S. § 118D(C)). If you earn 60% of the combined adjusted income, you are responsible for 60% of the obligation.
The parent with less parenting time generally pays their share to the parent who has the child most of the time.
What Counts as “Income”? Almost Everything.
Parents are often surprised by how broad the definition is. Gross income includes earned income — salaries, wages, tips, commissions, bonuses, severance, military pay — and passive income, such as rental income, dividends, interest, pensions, Social Security benefits, unemployment and disability benefits, and even gifts, prizes, and gambling winnings (43 O.S. § 118B).
A few things are excluded, including child support received for other children, means-tested public assistance like TANF and SSI, the child’s own income, and foster care payments. And parents who already support other children — under a prior court order or in their own home — may qualify for a deduction that adjusts gross income before the calculation (43 O.S. § 118C).
Two situations deserve special attention:
- Self-employment. Business income counts, minus ordinary and reasonable expenses — but what the IRS allows isn’t automatically what the child support calculation allows. Accelerated depreciation, for example, doesn’t reduce income for support purposes (43 O.S. § 118B).
- Imputed income. The court uses whichever of three figures is most equitable: current monthly income, the average for months actually worked last year, or imputed income (43 O.S. § 118B(C)(1)). Income can be imputed whenever current or average income is unavailable or simply is not the most equitable measure — including, but not limited to, when a parent is willfully unemployed or underemployed. In imputing, the court may consider area and industry wages, education and ability to work, minimum wage at not less than 25 hours per week, and lifestyle and valuable assets — even assets held in a current spouse’s name (43 O.S. § 118B(C)(3)). Quitting a job doesn’t make child support go away.
The Parenting Time Adjustment: The 121-Overnight Threshold
If the parent paying support has the children for at least 121 overnights per year, they may qualify for a parenting time adjustment that changes the formula to account for the expenses of substantial time with the kids (43 O.S. § 118E). The adjustment scales with overnights and is presumptive, not automatic — a court can decline it if it wouldn’t serve the child’s best interests or if the added time doesn’t actually produce greater expenditures (43 O.S. § 118E(C)). For these purposes the paying parent is generally the one with 182 or fewer overnights per year (43 O.S. § 118A), and a parent granted more than 205 overnights cannot be ordered to pay base child support at all (43 O.S. § 118E(D)(5)).
One caution: the adjustment is based on overnights actually ordered — and a parent who then fails to exercise those overnights can be ordered to repay the difference and lose the adjustment going forward (43 O.S. § 118E). Overnight counts matter, both in negotiation and in practice.
What Gets Added On Top
The base obligation isn’t the whole picture. The children’s share of the health insurance premium is allocated between the parents in proportion to their adjusted gross incomes and added to the base obligation. If the paying parent carries the insurance, they receive a credit for the other parent’s allocated share; if the receiving parent carries it, the paying parent owes that allocated share in addition to base support — the credit runs in one direction only (43 O.S. § 118F(H)). The insurance must also be reasonable in cost — the child’s share of the premium generally cannot exceed 5% of the covering parent’s gross income — and accessible, meaning appropriate providers within 60 miles one way of the child’s home (43 O.S. § 118F(D)). Work-related child care costs are allocated the same way as the premium (43 O.S. § 118G), and in some circumstances the court can account for child care during a job search or schooling (43 O.S. § 118G(E)). Uninsured medical, dental, and similar expenses are also split proportionally unless the parents agree otherwise and the court approves (43 O.S. § 118F(I)). These add-ons often move the final number more than parents expect — especially with daycare-age children.
Can the Court Order a Different Amount?
Yes, but it’s the exception. The guideline amount is a rebuttable presumption (43 O.S. § 118). A court can deviate only if the deviation is in the child’s best interests and one of three things is true: the guideline amount is unjust or inappropriate under the circumstances; both parties are represented by counsel and have agreed to a different disposition; or one party is represented by counsel and the deviation benefits the unrepresented party. The court must then make specific findings of fact (43 O.S. § 118H(B)–(C)). One floor is absolute: no deviation may seriously impair the receiving parent’s ability to maintain minimally adequate housing, food, and clothing for the children, or to provide other basic necessities (43 O.S. § 118H(A)). Deviations can also add to the number — extraordinary educational expenses and special expenses like private school, camp, or travel sports can be added on top of the guideline amount (43 O.S. § 118H(G)–(H)).
Changing an Existing Order
Child support isn’t set in stone. Orders can be modified when there’s a material change in circumstances — an income increase or decrease, changed child care or insurance costs, or a child aging out of support (43 O.S. § 118I).
The single most important rule: modification is not retroactive. A new amount generally takes effect the first day of the month after the motion to modify is filed — not when your income actually changed (43 O.S. § 118I). If you lose your job or take a pay cut, waiting to file means paying (or forgoing) the old amount for every month you wait. File promptly.
Where the Formula Tops Out — and Pauses
The guideline schedule runs up to $15,000 in combined monthly gross income and six children; above either cap, the court starts from the capped figure and sets any additional amount itself (43 O.S. § 119(B)–(C)). And if a parent is incarcerated for 180 or more consecutive days, the support obligation is presumptively abated during the incarceration and resumes after release — though anything past-due before the abatement still stands (43 O.S. § 118I(E)).
Get the Number Right the First Time
Oklahoma’s guidelines are formula-driven, but the inputs are where cases are won and lost: what counts as income, what a self-employed parent really earns, whether income should be imputed, and how overnights are counted. Small input errors compound every month for years.
Visit our Child Support practice page to learn how we approach these cases — setting an amount, disputing an income figure, or modifying an existing order. Call (405) 507-1800 or schedule a consultation online today.