Compare Child Support Guidelines by State

The two basic models

Most states use one of two approaches. The first is a percentage model. Texas is the clearest example: the paying parent’s net resources are multiplied by a percentage that rises with the number of children. Wisconsin works the same way with 17% to 34% of the paying parent’s income, plus a shared-placement formula. The other parent’s income is not part of the basic calculation. The second is an income-shares model. California, Florida, Illinois, Ohio, Indiana, Georgia, Michigan, New York, Pennsylvania, New Jersey, North Carolina, Virginia, Washington, Arizona, Massachusetts, Tennessee, Maryland, and Colorado use some version of it: both parents’ incomes are combined, a basic obligation is read from a schedule or formula, and each parent is assigned a share in proportion to income.

The label matters less than the details. A state can call itself income-shares and still use a very different income definition, parenting-time rule, or add-on rule from its neighbor. That is why the calculators on this site are state-specific and why the pages do not share a single “national” formula. The guideline tables by state show the arithmetic side by side.

Income: the input that moves the number most

Every guideline starts with income, but states do not agree on what income means. Texas starts with gross income and subtracts federal tax, Social Security, Medicare, and specific deductions. California uses net disposable income under Family Code Section 4059. Ohio’s schedule is based on annual income. Indiana uses weekly adjusted income. Georgia uses adjusted gross income, which subtracts half of self-employment tax and prior support. Michigan uses a formula-specific net income. New York starts with annual gross income and subtracts FICA and New York City or Yonkers income tax. Pennsylvania subtracts only the deductions its rule lists: taxes, FICA, non-voluntary retirement, union dues, and alimony paid. New Jersey works in weekly amounts and allows withholding taxes, mandatory retirement and union dues, and prior support orders. North Carolina starts with monthly gross income and subtracts only prior support and responsibility for other children. Virginia uses monthly gross income with no standard deduction. Washington starts with net income after taxes, FICA, state deductions, and union dues. Arizona starts from gross income and adjusts for maintenance and children of other relationships. Massachusetts works in weeks, with gross income less the children’s insurance premiums and support paid under another order. Tennessee starts with gross income and subtracts self-employment tax and credits for other children. Maryland subtracts prior support paid, alimony paid, and an allowance for other children in the home. Colorado adjusts gross income for maintenance and prior support orders. Wisconsin applies a percentage to income available for child support.

The practical consequence is simple: entering gross salary in a net-income calculator produces an estimate that is too high, and entering take-home pay in a gross-income calculator produces an estimate that is too low. The state page tells you which figure to use. If you are unsure, the official calculator or a pay stub is the better source. The guide to variable income explains how overtime, bonuses, and self-employment profit are averaged.

Income is also broader than salary. Overtime, bonuses, commissions, self-employment income, disability benefits, retirement income, and imputed income can all be part of the guideline. A single unusual month should not drive the estimate; use a representative average or the figure the court is likely to accept.

Parenting time: formula, adjustment, or deviation

Parenting time is the second-biggest source of variation. California builds the higher earner’s timeshare directly into the Section 4055 formula. Florida applies a 1.5× adjustment when each parent has at least 20% of the overnights. Illinois uses a shared-parenting calculation at 146 overnights. Pennsylvania adjusts at 40% of the overnights. New Jersey uses a separate shared-parenting worksheet at 28% of overnights. North Carolina switches to Worksheet B for joint or shared physical custody. Virginia uses a shared custody formula above 90 days a year. Washington treats significant time as a deviation from the standard calculation. Arizona uses a Parenting Time Table from 20 to 164 or more days. Massachusetts uses one worksheet for shared and split plans, with parenting time as a deviation. Tennessee compares variable costs on worksheet lines 5 and 6. Maryland switches to Worksheet B at 128 nights with each parent. Colorado applies a shared parenting time credit from the first overnight. Wisconsin uses the shared-placement formula once each parent has 25% of the overnights. Ohio, Indiana, and Georgia use separate worksheets or credits that this site does not reproduce. New York and Texas have no timeshare variable in the basic guideline.

A common misconception is that 50/50 custody automatically means no support. In an income-shares state, equal time can still produce a payment if one parent has significantly more income. In a percentage state such as Texas, the guideline does not contain a timeshare discount at all. The state page explains which rule applies. The guide to 50/50 custody and child support compares the twenty states.

Add-ons and deviations

Basic support is not the whole order. Childcare, health insurance, uninsured medical expenses, dental, vision, and sometimes travel or extracurricular costs are add-ons. States usually allocate them between the parents, but the court can order a different split. Add-ons can increase the final order even when the basic guideline is modest. The guide to child support add-ons covers each one in detail.

Courts can also deviate from the guideline. The reasons vary by state, but they often include special needs, extraordinary expenses, a parent’s travel costs, or a significant disparity in the parents’ circumstances. A guideline estimate is a starting point; a deviation is a judicial decision that no calculator can predict.

Common mistakes when comparing states

The most common mistake is comparing a gross-income estimate from one state with a net-income estimate from another. A $6,000 gross salary and a $6,000 net income are not the same input, even though they look the same in a table. The second most common mistake is assuming that a 50/50 schedule produces the same result everywhere. California, Florida, and Wisconsin apply their parenting-time rule in the estimate. Texas and New York keep parenting time out of the guideline entirely, and the other states use worksheets that this site does not reproduce.

A third mistake is ignoring add-ons. A state with a lower basic obligation can produce a higher final order if childcare and health insurance are significant. A fourth is assuming that the guideline is the order. Courts can deviate, and the reasons for a deviation are often facts that a calculator never sees.

How to use the state calculators

1. Open the page for your state.
2. Read the income label carefully. Enter net income, gross income, or weekly income exactly as the page asks.
3. Enter the number of children covered by the order.
4. If the page has a parenting-time field, enter the percentage of overnights. If it does not, the page assumes a primary custodial schedule.
5. Read the result and the “what this estimate leaves out” list before relying on it.

If your situation includes shared custody, a self-employed parent, a parent outside the state, a prior support order, or a request to deviate, use the official calculator and talk to a family law attorney. The estimate is a way to understand the structure of the number, not a substitute for the order.

Frequently asked questions

The calculators are educational estimates. They are not legal advice and do not create an attorney-client relationship. See the methodology for the sources and update policy.