How Florida calculates child support
Florida uses an income-shares model, set out in Fla. Stat. § 61.30. The idea is simple: children should receive the same share of parental income they would have received if the household were intact. The court combines both parents' monthly net incomes, looks up the guideline amount for that combined income and the number of children in the statutory schedule, and divides responsibility for that amount in proportion to each parent's share of the combined income.
Two adjustments matter in almost every case. First, child care costs required for a parent's work and the children's health insurance premiums are added on top of the basic obligation and allocated between the parents. Second — and this is the one that surprises people — the amount of time-sharing changes the math.
The 20% overnight rule
When each parent has the children for at least 20% of the overnights in the year — 73 nights — the statute switches to a "substantial time-sharing" calculation. The basic obligation is multiplied by 1.5, each parent's share is computed, each share is multiplied by the percentage of overnights the children spend with the other parent, and the two obligations are offset. The practical effect: the closer the schedule gets to equal, the more the transfer payment shrinks — but it rarely reaches zero unless incomes are nearly equal too.
This is why support and time-sharing cannot be negotiated in separate rooms. A schedule that moves a handful of overnights across the 73-night line changes the support calculation categorically — a fact worth understanding before you agree to anything.
Want a ballpark? The guideline estimator on this site uses the actual statutory schedule and the overnight adjustment. It's an estimate only — the real calculation turns on properly computed net incomes and add-ons — but it will tell you what neighborhood your case lives in.
Where guideline cases are actually fought
- Net income. Gross income minus allowable deductions — taxes, mandatory retirement, union dues, health insurance for the parent, court-ordered support for other children. Overtime, bonuses, second jobs, and self-employment income all count, and self-employment is where numbers most often need forensic attention.
- Imputed income. A parent who is voluntarily unemployed or underemployed can have income imputed — the calculation runs on what they could earn, not what they choose to earn. Proving (or defending against) imputation is evidence work, not assertion.
- Deviations. The court may adjust the guideline amount within 5% for any relevant factor, and beyond 5% only with written findings — for example, extraordinary medical or educational expenses, a child's independent income, or seasonal income patterns.
Modification and enforcement
Support orders can be modified when circumstances change substantially — a lasting change in either parent's income, in the children's needs, or in the time-sharing schedule actually being exercised. Waiting costs money: modification generally reaches back only to the date the petition is filed, not to the date the job was lost. On the enforcement side, Florida offers real teeth — income withholding, contempt, license suspension, judgment liens — and Shelley handles both pursuing unpaid support and defending parents who have genuinely lost the ability to pay.
Key law: Fla. Stat. § 61.30 (child support guidelines; substantial time-sharing at 20% of overnights); § 61.13 (support orders); § 61.14 (modification).
Common questions about child support
Not really. Child support is the child's right, not the parents' — courts must review any agreement against the guidelines and will not rubber-stamp a waiver. Parents have some room to negotiate within and around the guideline figure, especially with a justified deviation, but "we agreed on zero" is not a plan a Florida court will simply accept.
No — a common and expensive myth. Equal overnights trigger the substantial time-sharing formula, but if one parent earns more, the offset still produces a transfer payment. Support only nets near zero when both time and incomes are close to equal.
Florida law anticipates this: where unemployment or underemployment is voluntary, the court calculates support on imputed income — recent work history, qualifications, and prevailing local wages. It has to be proven with evidence, which is exactly the kind of case preparation this office does.
Generally until a child turns 18 — or until high school graduation, no later than 19, for a child on track to graduate. Support can continue for adult children with significant disabilities. Each child's end date should be written into the order correctly at the start; fixing it later is harder.
The estimator uses Florida's actual statutory schedule and the overnight adjustment, so it's a genuine guideline ballpark — but it can't compute your correct net incomes, add-ons, or deviations. Treat it as orientation, not an answer. It is an estimate only, not legal advice; have Shelley run the exact calculation for your situation.
Or call the office at (863) 298-0606. Located at 290 Cypress Gardens Blvd, Suite 10, Winter Haven.