A man in his forties paid a $3,500 retainer expecting a fight about how much child support he would owe, and spent most of the first meeting watching his attorney fill in a two-page state worksheet instead. Gross monthly income for each parent, health insurance premium for the children only, work-related child care, number of overnights, other children supported. The number that came out at the bottom was within about forty dollars of what the state's free online calculator had produced the week before. What the retainer actually bought was a careful argument about four of the inputs, not about the result.
That distinction is the whole of it. Every state runs child support through a guideline formula, and the federal framework requiring states to have those guidelines and to review them periodically sits with the Department of Health and Human Services, which oversees the child support program nationally. Judges can deviate, but they have to write down why, and routine deviations are rare. So a careful reader stops asking what a lawyer thinks the support should be, and starts asking which lines on the worksheet are genuinely contestable in their particular facts.
Income shares and percentage of obligor, and why the difference shows up in your case
Most states use an income shares model, which adds both parents' incomes, looks up the total in a table of what an intact household at that income typically spends on children, and splits that figure in proportion to each parent's share of the combined income. A handful use a percentage-of-obligor model, which largely ignores the receiving parent's income and applies a flat percentage to the paying parent's income by number of children. The practical consequence is direct: under income shares, the other parent's earnings, raises, and second job all move your number, and under a percentage model they mostly do not. Knowing which model your state uses tells you where discovery is worth paying for.
Where imputed income enters, and how it is actually decided
The line marked gross monthly income is the softest number on the page, and it is where most real disputes live. A salaried employee with a single W-2 has almost nothing to argue about. A commissioned salesperson, a contractor paid on a 1099, an owner of an S corporation who takes a modest salary and larger distributions, or a parent who quit a $95,000 job for one paying $48,000 all present a genuine question. Courts can impute income based on earning capacity, recent work history, local prevailing wages, or a finding of voluntary underemployment. That is an evidentiary fight, and it is one of the few places where hours billed change the outcome.
Overnights, schedules, and the number that feeds back into the money
Parenting time is usually negotiated against a small set of familiar patterns: alternating weekends with a midweek dinner, a 5-2-2-5, a week on and week off, or a 2-2-3 rotation for younger children. Many states apply a shared parenting adjustment once the non-primary parent passes a threshold of overnights per year, often somewhere near ninety or a hundred and twenty depending on the statute, and the support figure can step down noticeably at that line. This is why the schedule and the money cannot be discussed separately, and why a reader should ask early what their state's threshold is and how far the current proposal sits from it.
What a careful reader checks before agreeing to anything
Run the state calculator yourself, twice, with your own numbers and then with the numbers the other side is asserting, and note the gap. Confirm which income figure the worksheet wants, gross or net, and whether overtime and bonuses are averaged over one year or three. Check whether the health insurance line takes the whole family premium or only the children's portion, since the difference can be a hundred dollars a month. Ask what add-ons your state treats as mandatory rather than discretionary: uninsured medical, child care, extracurriculars, private school. Then ask which of those lines your attorney thinks is actually movable.
The useful conversation with a lawyer, once the formula is understood, is narrow and specific: what is my income for guideline purposes, what is theirs, how many overnights, and is there a documented reason for deviation. Those four questions are worth real money to answer well. The arithmetic downstream of them is not a negotiation, and treating it as one is the most common way people spend three thousand dollars discovering what a free worksheet would have told them in an afternoon.