Louisiana · La. R.S. 9:315 et seq.
How it works
Louisiana uses the income-shares model: the support obligation is the amount the parents would spend on the children if the household were intact, divided between them in proportion to income. Every step below is what the calculator does, with the rule that authorizes it.
Step 1
Determine each parent's income
La. R.S. 9:315.2(A)
Start from each parent's gross income, then subtract pre-existing court-ordered child support actually paid for other children. The result is each parent's adjusted gross income. The income page covers self-employment, imputation, and what counts as income.
Step 2
Combine income and read the schedule
La. R.S. 9:315.2(C); 9:315.19
Add both parents' adjusted gross incomes and read the basic obligation from the schedule at the nearest $50 row for the number of children. The schedule runs to $40,000 combined monthly income; the lowest row builds in a $100 minimum.
Step 3
Prorate by income share (Worksheet A)
La. R.S. 9:315.2(C)–(D); 9:315.8
Each parent's percentage share of combined income is their share of the basic obligation. The non-domiciliary parent pays their share to the domiciliary parent.
Step 4
Add the mandatory add-ons
La. R.S. 9:315.3–9:315.5
Net work-related childcare (9:315.3), the children's health-insurance premium (9:315.4), and extraordinary uninsured medical above $250/child/year (9:315.5) are added to the obligation and prorated by income share. A parent who pays an add-on directly is credited for it. Extraordinary educational expenses (9:315.6) are discretionary — handled as a deviation rather than an automatic add-on.
Step 5
Shared custody — Worksheet B (1.5× cross-multiply, with a ceiling)
La. R.S. 9:315.9
For approximately-equal custody, the basic obligation is multiplied by 1.5 (the duplicated-household premium). Each parent's theoretical obligation is then cross-multiplied by the other parent's actual percentage of physical-custody time, and the two are offset — the higher pays the difference. The shared-custody result is capped at what the obligor would owe as the domiciliary parent: a ceiling, never a floor. Split custody (different children domiciled with different parents) uses a separate worksheet per group (9:315.10).
Step 6
Self-sufficiency reserve and the minimum order
La. R.S. 9:315(B)(1); 9:315.1(C)(2)
The schedule incorporates a self-sufficiency reserve for low-income obligors, and the lowest schedule row builds in a $100 minimum obligation. A combined adjusted income of $950 or less is also an express deviation ground.
Step 7
Above the schedule, and deviations
La. R.S. 9:315.13(B)(1); 9:315.1(B); Falterman v. Falterman
Above $40,000 combined monthly income the highest scheduled amount is a floor; any additional support is within the court's discretion based on the children's needs and the parents' circumstances. A court may deviate from the presumptive amount in either direction with written findings that the guideline amount would not be in the child's best interest or would be inequitable.