How Florida Calculates Child Support: Guidelines Explained

The Income Shares Model

Under Fla. Stat. § 61.30, Florida calculates child support using an income shares model. The idea is that a child should receive the same proportion of parental income they would have received if the parents lived together. In practice, that means the court combines both parents' net monthly incomes, looks up a basic support obligation on the statutory guidelines schedule, and then divides that obligation between the parents based on each parent's share of the combined income. The guideline amount that comes out of this formula is presumptively the amount the court must order — a judge can't simply pick a different number because it feels more reasonable, without a specific legal basis for deviating.

Step One: Figuring Out Gross and Net Income

The calculation starts with each parent's gross monthly income, which is defined broadly. It includes salary and wages, bonuses, commissions, and overtime; self-employment and business income; disability and workers' compensation benefits; unemployment compensation; retirement, pension, and annuity payments; Social Security benefits; spousal support received from a prior marriage; interest, dividends, and rental income; and most other recurring income sources. If a parent is voluntarily unemployed or underemployed, the court can impute income based on that parent's recent work history, qualifications, and prevailing wages in the community, rather than accepting an artificially low reported income.

From gross income, the statute allows a specific list of deductions to reach net income: federal, state, and local income taxes; FICA or self-employment tax; mandatory union dues; mandatory retirement contributions; health insurance premiums (excluding the portion covering the child); court-ordered support actually paid for other children; and spousal support paid under a prior order. Each parent's net income is calculated separately, then the two figures are added together to get the combined net income used for the rest of the calculation.

Step Two: The Guidelines Schedule and Each Parent's Share

Once combined net income is known, it's run against the guidelines schedule in the statute, which lists a minimum child support obligation for combined income levels and for one through six children. For combined incomes above the top of the schedule, the obligation is the guideline maximum plus a set percentage of income over that threshold, with the percentage increasing based on the number of children. Each parent's individual dollar share of that total obligation is then based on their percentage share of the combined net income — a parent earning 60 percent of the combined income is generally responsible for 60 percent of the basic obligation.

Substantial Time-Sharing Changes the Math

Overnights matter as much as income. Once a parent has time-sharing of at least 20 percent of the annual overnights — roughly 73 nights a year — Florida applies a different calculation known informally as the gross-up formula. Each parent's share of the basic obligation is multiplied by 1.5 to account for the added cost of maintaining two homes for the child, and the result is further adjusted based on each parent's actual percentage of overnights. This adjustment doesn't automatically zero out support in a 50/50 schedule; if the parents' incomes are unequal, the higher earner typically still owes the lower earner some amount, just usually less than under a standard, non-shared schedule. Time-sharing arrangements below the 20 percent threshold can still be raised as a reason for the court to deviate from the guideline amount, just under a different, more discretionary standard.

What Gets Added on Top: Child Care and Health Insurance

Work- or education-related child care costs and the child's share of health insurance premiums, along with uncovered medical, dental, and prescription expenses, are added to the basic obligation and then allocated between the parents in the same proportional way as the base amount. A parent who has already prepaid some of these costs directly gets credit against what they owe.

When Courts Deviate From the Guideline Amount

The guideline number isn't absolute. A court may order an amount that varies up to 5 percent from the guideline without any special explanation. A larger deviation requires a written finding explaining why the guideline amount would be unjust or inappropriate, based on factors like extraordinary medical or educational expenses, a child's age, seasonal income swings, the child's own independent income, or a parenting arrangement that falls just short of the 20 percent overnight threshold. The statute also caps a single support obligation at 55 percent of the paying parent's gross income absent unusual circumstances.

Modifying Child Support Later

Child support orders aren't locked in permanently. A parent can seek a modification when there's been a substantial change in circumstances — a significant change in either parent's income, a change in the time-sharing schedule, or a change in the child's needs. As a general guide, the recalculated guideline amount typically needs to differ from the existing order by at least 15 percent or $50, whichever is greater, before a court will treat that difference alone as a substantial change justifying modification.