Quick answer: South Dakota uses an income-shares model in SDCL 25-7-6.1 to 25-7-6.29. Each parent’s monthly net income is gross income less income tax at the single-taxpayer monthly payroll rate, Social Security and Medicare tax, retirement contributions up to 10% of gross, unreimbursed employee business expenses and payments on other support orders. The two net incomes are added, the obligation schedule in SDCL 25-7-6.2 (up to $30,000 a month, one to six children) gives the basic obligation, and the non-custodial parent’s proportionate share is the order. The emboldened low-income areas of the schedule include a self-support reserve of $871: if the obligation using only the non-custodial parent’s income falls there, it is compared with the proportionate share and the lesser applies. The children’s health insurance is apportioned by income and credited to the parent who pays it, and the court may allocate reasonable child care, with a federal credit counted at 25%. If a custody order has a detailed shared parenting plan with at least 180 nights in each home, the court may grant a cross credit: the basic obligation times 1.5, apportioned by income, applied to the nights with the other parent and offset. For 6 or more nights a month the court may also grant an abatement of 38% to 66%. The guideline amount is a presumption; deviations need specific findings.
How the South Dakota schedule works
- Net income, the schedule and shares. See how the South Dakota schedule works.
- Shared parenting and abatements. See the shared parenting cross credit and abatement.
- The reserve, health insurance and child care. See the self-support reserve, health insurance and child care.
What this calculator checks
The calculator follows the statutes and the schedule published in SDCL 25-7-6.2 (582 rows from $0 to $30,000, with the emboldened reserve cells read from the statute’s own formatting), computes federal income tax with the 2026 IRS Publication 15-T single-filer percentage method that the statute’s “single taxpayer, monthly payroll period” rule points to, and was checked against an independent re-implementation. The statute does not say how child care is allocated; the calculator shares it by net income like the health insurance premium. It does not compute the 6.14 abatement, self-employment tax or deviations.
Child support across South Dakota
The guidelines apply in every circuit court, from Sioux Falls, Rapid City, Aberdeen, Brookings, Watertown or Mitchell. Deviation requires specific findings on the factors in SDCL 25-7-6.10, and a total obligation above 50% of the obligor’s net income is presumed to be a financial hardship.
Frequently asked questions
How is child support calculated in South Dakota?
Both parents' monthly net incomes are added, the SDCL 25-7-6.2 schedule gives the basic obligation for the number of children, and the non-custodial parent pays his or her proportionate share.
What income does South Dakota use for child support?
Net income: gross income less single-taxpayer income tax at the monthly payroll rate, Social Security and Medicare, retirement contributions up to 10% of gross, business expenses and other support payments.
How many nights make shared parenting in South Dakota?
At least 180 nights a year in each parent's home, with a detailed shared parenting plan; the court may then grant a cross credit.
What is the South Dakota self-support reserve?
$871 a month, included in the emboldened areas of the schedule; the lesser of the obligor-only amount and the proportionate share applies there.
What is the highest income in the South Dakota schedule?
$30,000 of combined monthly net income; above it the court sets support at an appropriate level based on the child's needs and standard of living.