Calculation is client-side, income figures are never transmitted or stored.
How Oklahoma Child Support Is Calculated
- Add both parents' gross monthly income to get combined income, then look up Oklahoma's Schedule of Basic Child Support Obligations for the total number of children. Oklahoma's schedule is a true step function: the row for the income level equal to or above your combined income applies as a flat amount, not interpolated.
- Each parent's share of that total (plus childcare and health insurance costs) is their percentage of combined income.
- If the paying parent has 121 or more overnights per year (a Parenting Time Adjustment), the combined obligation is multiplied by a stepped factor (2.0 for 121-131 overnights, 1.75 for 132-143, 1.5 for 144+), split by income share, then each parent's share is multiplied by the percentage of time the child spends with the OTHER parent, and the two amounts are offset -- capped so the result never exceeds the standard amount.
- Above $15,000/month combined income, the schedule does not extend automatically -- courts add a discretionary amount on top of the $15,000-level amount.
Oklahoma Child Support Worksheet Walkthrough
Example: Parent A earns $2,500/month gross, Parent B earns $1,500/month gross (combined $4,000). There are two children, who live primarily with Parent B; Parent A has 130 overnights/year (a Parenting Time Adjustment, since it exceeds 121).
- Combined gross monthly income: $2,500 + $1,500 = $4,000.
- Schedule of Basic Child Support Obligations at $4,000 combined, two children: $837.
- Parenting Time Adjustment factor at 130 overnights (121-131 range): 2.0. Adjusted combined obligation: $837 x 2.0 = $1,674.
- Parent A's share ($1,046.25, their 62.5% income share) x Parent B's time share (64.4%) = $673.60. Parent B's share ($627.75, their 37.5% income share) x Parent A's time share (35.6%) = $223.60.
- Offset: $673.60 - $223.60 = $450, capped at the standard (non-adjusted) amount of $523 -- since $450 is lower, Parent A pays $450/month.
How This Calculator Works — Formula & Constants
Source: Oklahoma Department of Human Services — Child Support Services (43 O.S. §§ 118-119) · Calcul déterministe — no AI, no arbitrary estimate.
Constants used
| Constant | Value | Source |
|---|
Formula
base_obligation = schedule_lookup(combined_income, children)
share_B = parentB_income / combined_income
total_obligation = base_obligation + childcare_cost + health_insurance_cost
obligation_B = total_obligation × share_B
obligation_B = obligation_B × (1 - custody_credit(overnights))
Deterministic calculation based on Oklahoma's official guideline schedule table. Verify against Oklahoma's official calculator for a court-ready figure.
FAQ
How is child support calculated in Oklahoma?
Add both parents' gross monthly income to get combined income, then look up Oklahoma's Schedule of Basic Child Support Obligations for the total number of children. Oklahoma's schedule is a true step function: the row for the income level equal to or above your combined income applies as a flat amount, not interpolated. Each parent's share of that total (plus childcare and health insurance costs) is their percentage of combined income. If the paying parent has 121 or more overnights per year (a Parenting Time Adjustment), the combined obligation is multiplied by a stepped factor (2.0 for 121-131 overnights, 1.75 for 132-143, 1.5 for 144+), split by income share, then each parent's share is multiplied by the percentage of time the child spends with the OTHER parent, and the two amounts are offset -- capped so the result never exceeds the standard amount. Above $15,000/month combined income, the schedule does not extend automatically -- courts add a discretionary amount on top of the $15,000-level amount.
What is Oklahoma's Parenting Time Adjustment?
When the paying parent has 121 or more overnights per year, Oklahoma multiplies the combined base obligation by a stepped factor (2.0, 1.75, or 1.5 depending on the exact overnight count), then recalculates each parent's share factoring in how much time the child spends with each parent, offsetting the two amounts. The result is capped so it never exceeds what the paying parent would owe without the adjustment.
Is Oklahoma's schedule a smooth curve or literal brackets?
Literal brackets. Oklahoma's Schedule of Basic Child Support Obligations (43 O.S. § 119) states that the amount applies for combined income 'equal to or above' each listed row -- a true step function, not a value meant to be interpolated between rows.
What happens above the $15,000/month cap in Oklahoma?
The schedule does not automatically extend. Courts use the amount computed for $15,000/month combined income as a base, then add an additional amount determined case-by-case (43 O.S. § 119).
Methodology & Source
Formula model: income shares. Effective 2009-07-01, guideline version 2013-OK-v1, last reviewed 2026-07-13.
Official source: Oklahoma Department of Human Services — Child Support Services (43 O.S. §§ 118-119) (43 O.S. §§ 118, 118E, 119).
Above $15,000/month combined gross income, Oklahoma's guideline schedule does not extend automatically -- the amount is that computed for $15,000/month plus an additional amount determined by the court (43 O.S. § 119). Above 205 overnights/year for the paying parent, this calculator does not model the different calculation that applies. This calculator does not model Split Physical Custody (each parent primary for at least one different child) or the discretionary Cash Medical Support obligation (a separate 5%-of-gross-income-capped add-on when health insurance isn't available).
Guideline figures transcribed from the primary source above and cross-checked against Oklahoma's official calculator/worksheet for multiple test scenarios — see our verification methodology.