Child Support Calculator
A simplified, generic income-shares estimate of monthly child support from both parents' incomes, number of children and parenting time. Every US state has its own official guidelines and calculator — use this for orientation only, not for filing.
Reviewed by the CalcCafe editorial team · Last updated 18 July 2026 · How we test our tools
Example
One parent grosses $6,000 a month and the other $4,000, with two children and 20% parenting time for the paying parent. Combined income is $10,000. Under this generic model, two children carry a 25% basic obligation: $2,500 a month. The higher earner's share is 60% of that ($1,500), reduced by the 20% parenting-time credit to an estimated $1,200 per month. Your state's actual guideline could produce a meaningfully different number in either direction.
How it works
This tool uses a simplified, generic version of the income-shares model that most states base their guidelines on. Combined income = both parents' gross monthly incomes. A basic support obligation is taken as a percentage of combined income by number of children — 17% for one child, 25% for two, 29% for three, 31% for four, 33% for five and 35% for six in this generic table. Your share of the obligation is proportional to your share of combined income, and it is then reduced by your parenting-time percentage as a simple credit: support = obligation × (your income ÷ combined income) × (1 − parenting time). Real state formulas use detailed schedules rather than flat percentages, apply parenting-time adjustments very differently (many only above a threshold of overnights), and add health insurance and childcare on top — so treat this strictly as orientation.
Good to know
US states use three families of guideline: the income-shares model (the large majority of states), which splits an estimated cost of raising the children in proportion to each parent's income; the percentage-of-income model (a handful of states, such as those taking a flat share of only the payor's income); and the Melson formula (a few states), which reserves a self-support amount for each parent first. The same facts can produce noticeably different obligations from one state line to the next.
What counts as income is broader than salary: wages, self-employment profit, bonuses, commissions, rental income and unemployment benefits typically count, and courts can impute income to a parent who is voluntarily unemployed or underemployed. Gross versus net starting points also differ by state, which alone shifts results substantially.
Parenting-time adjustments vary enormously and are the least standardized piece. Some states apply a credit only after a threshold number of overnights (for example 20–30% of the year), some use cross-multiplier formulas that change the result sharply near 50/50 schedules, and a few barely adjust at all. The simple proportional credit used here is a smoothed approximation and will not match any particular state's treatment, especially near equal custody.
Real orders also include add-ons the model above ignores: the children's health insurance premiums, unreimbursed medical costs, and work-related childcare are usually split on top of the basic obligation, and courts can deviate from guidelines for special needs, high incomes or agreed arrangements. Every state publishes an official guideline calculator or worksheet — find yours through your state's child support agency (coordinated federally by the Office of Child Support Services at ACF) and rely on that, plus a family law attorney, for any figure used in filing or negotiation. This page makes no promise of accuracy for any state or case.
Frequently asked questions
How is child support actually calculated in my state?
By your state's own guideline — most use an income-shares model with a published schedule, others use percentage-of-income or the Melson formula, layered with parenting-time rules and add-ons for health insurance and childcare. This page uses a generic simplified model for orientation; your state's official calculator is the only reliable figure and courts can still deviate from it.
Does 50/50 custody mean no child support?
Not necessarily. In most states a parent with meaningfully higher income still pays support at equal parenting time, because guidelines aim to balance the children's standard of living across both homes. Exact treatment of shared custody varies more between states than any other part of the formula.
Is my data uploaded anywhere?
No — this calculator runs entirely in your browser. Income and custody figures never leave your device, and nothing is stored on any server.
Is this child support calculator free?
Yes — completely free with no sign-up. It is an educational estimate from a generic model, not legal advice; use your state's official calculator and an attorney for real figures.
People also ask
What income counts for child support?
Generally all regular income: wages, self-employment profit, bonuses, commissions, overtime, rental income and unemployment benefits. Many states start from gross income, some from net, and courts can impute income to a parent who is voluntarily earning below capacity.
Is child support tax deductible or taxable?
Neither. Child support is not deductible by the parent who pays it and is not taxable income to the parent who receives it, under federal tax law. This differs from alimony rules for older divorce agreements.
Can child support be changed later?
Yes. Either parent can ask the court to modify support after a substantial change in circumstances — a significant income change, job loss, custody-schedule change or new medical needs. Until a court modifies the order, the existing amount legally stands, so file promptly when circumstances shift.
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Sources & references
These tools follow our methodology and provide educational estimates only — verify important figures with a qualified professional.