Methodology and Sources
Family Support Math publishes free estimates of child support and spousal support for U.S. families. This page explains how the numbers are built, which official sources are used, and where the limits are.
Updated November 12, 2026 Sources and methodology
What the calculators do
Each state calculator applies the state’s published guideline to the income, children, and parenting-time inputs you provide. The output is the basic obligation: the core monthly support amount before add-ons and before any deviation. The page shows the formula, the income definition, the table or rate used, and a worked example.
The calculators are deliberately narrow. They do not try to reproduce every worksheet line, every deduction, or every discretionary factor. A narrow estimate that explains its assumptions is more useful than a broad estimate that hides them.
Primary sources by state
| State | Primary source | What the calculator uses |
|---|---|---|
| Texas | Tex. Fam. Code Sections 154.062, 154.125; OAG 2026 tax charts | Percentage of monthly net resources, $11,700 cap |
| California | Fam. Code Sections 4055, 4059, 4062 | CS = K[HN − (H%)(TN)], current K-factors, multi-child multiplier |
| Florida | Fla. Stat. Section 61.30; Form 12.902(e) | Income-shares schedule, 1.5× shared-time adjustment |
| Illinois | 750 ILCS 5/505; HFS 2026 schedule | Income-shares schedule effective March 20, 2026 |
| Ohio | Ohio Rev. Code Sections 3119.021–3119.022; JFS 07767 | Annual income schedule, monthly = annual ÷ 12 |
| Indiana | Ind. Child Support Guideline 3; weekly schedule | Weekly adjusted income, income shares, monthly conversion |
| Georgia | O.C.G.A. Section 19-6-15; BCSO table | Adjusted gross income, BCSO table, income shares |
| Michigan | 2025 Michigan Child Support Formula | General Care bands, net family income, income shares |
| New York | N.Y. Fam. Ct. Act Section 413; Dom. Rel. Law Section 240(1-b); 2026 Standards Chart | Income shares, 17%–35% of combined income up to the $193,000 cap, self-support reserve |
| Pennsylvania | 23 Pa.C.S. Section 4322; Pa.R.C.P. 1910.16-2 to 1910.16-4; 2026 schedule | Income shares from the basic schedule, $1,255 self-support reserve, high-income formula above $30,000 |
| New Jersey | N.J.S.A. 2A:34-23; N.J. Court Rules, Appendix IX-A to IX-F | Weekly income shares from Appendix IX-F, $460 self-support reserve |
| North Carolina | N.C. Gen. Stat. Section 50-13.4; 2023 Child Support Guidelines; AOC-A-162 schedule | Income shares from the 2023 schedule, interpolated between $50 steps, shaded area for low incomes |
| Virginia | Va. Code Section 20-108.2; 2025 Acts chapter 702 schedule | Income shares from the 2025 schedule to $42,500, extrapolated between $50 steps, $68 statutory minimum |
| Washington | RCW 26.19.020 economic table; RCW 26.19.065 limits | Per-child table effective 2026 to $50,000, net income shares, $2,394 self-support reserve |
| Arizona | A.R.S. Section 25-320; Arizona Child Support Guidelines (2022, revised) | Income shares from the $750–$30,000 schedule, $50 rounding, self-support reserve test |
| Massachusetts | M.G.L. c. 208, Section 28; 2025 Child Support Guidelines (effective December 1, 2025) | Weekly chart with Table B factors to five children, shaded region and $8,654 cap |
| Tennessee | T.C.A. Section 36-5-101; Rule 1240-02-04-.09 schedule | Monthly adjusted gross income to $28,250, round up to the next $50, excess percentages above |
| Maryland | Md. Code, Family Law Section 12-204; 2022 schedule | Adjusted actual income to $15,000, extrapolated up, shared-custody worksheet |
| Colorado | C.R.S. Section 14-10-115; HB25-1159 schedule (effective March 1, 2026) | Adjusted gross income to $40,000, interpolated, $1,831.83 self-support reserve |
| Wisconsin | Wis. Stat. Section 767.511; Wis. Admin. Code DCF 150.035 | Percentage standard of 17%–34% and the shared-placement formula at 25% or more overnights |
What is deliberately excluded
- Childcare, health insurance, dental, vision, and extracurricular add-ons.
- Shared-parenting or parenting-time credits, except where the state page says they are included.
- Low-income adjustments and imputed income.
- Multiple-household formulas, split care, and prior support orders.
- Deviations for special needs, extraordinary expenses, or travel.
- Arrears, interest, and credits for benefits paid to the child.
- Alimony, except as a separate input in a state’s child support worksheet.
These are not minor details. A childcare add-on, a shared-parenting credit, or a deviation can change the final order by hundreds of dollars a month. The calculators are useful for orientation and budgeting; the official worksheet is the tool for a filing.
Update policy
Child support schedules and guidelines change on different cycles. Texas adjusts its cap periodically, Illinois publishes a new schedule each year, and several states revise their worksheets when the legislature meets. The site reviews each state page when a new schedule, statute, or official calculator is published, and the “last updated” date at the top of the page reflects the most recent review. Each worked example is recalculated against the published schedule when the page is reviewed.
If you spot a figure that is out of date, please use the contact page and include the state, the figure, and the official source. Corrections with a citation are prioritized.
Editorial policy and legal disclaimer
Family Support Math is written and maintained by Jesús Muentes, a software developer. I am not a lawyer. Every calculation follows the statute, court rule, or official schedule cited on each state page, and every page lists what the estimate leaves out.
Nothing here is legal advice, and using the site does not create an attorney-client relationship. Court orders, local rules, judicial discretion, and facts that are not captured by the calculator can change the result. If you need advice about your case, consult a licensed family law attorney in your state.
Contact
Questions, corrections, and source suggestions: [email protected]. We do not provide legal advice by email.