What's New

Washington D.C. calculator corrected and independently verified

The D.C. calculator had two bugs. First, the Basic Child Support Obligation schedule table contained incorrect values — roughly 45% too low across the board — because the D.C. Appendix I (§ 16-916.01a) uses annual combined income, and the original table was built from a different source that did not match the statute. The table has been rebuilt from the published D.C. Code with all 230 income rows. Second, the self-support reserve threshold was set to $1,304.50/month (100% of the federal poverty line) instead of the correct $1,734.58/month ($20,815/year — 133% of FPL as required by § 16-916.01(g)). Both fixes have been verified against the D.C. Child Support Services Division official calculator: $934/month for a paying parent earning $6,000/month and a receiving parent earning $4,000/month with one child; $1,049/month for equal incomes of $5,000/month each with two children.

Virginia calculator independently verified

The Virginia calculator was verified against the 2025 SB 805 schedule (Va. Code Ann. § 20-108.2, effective July 1, 2025) across three scenarios including sole custody and shared custody with 120 overnights. All results matched the statutory table within rounding.

Montana child support calculator added

Montana uses the Modified Melson Formula — a more involved approach than income shares that first sets aside a self-sufficiency allowance for each parent before calculating what remains for support. The calculator covers gross income and deductions for both parents, the primary caretaker allowance for the receiving parent, and a parenting time adjustment that kicks in at 110+ overnights per year.

Washington D.C. child support calculator added

D.C. uses an income-shares approach based on adjusted gross income rather than total gross — meaning existing child support payments, alimony paid, and health insurance premiums are subtracted from each parent's income before the schedule is applied. The calculator also handles D.C.'s shared custody rule: when the paying parent has at least 35% of overnight time (128+ nights), a 1.5x multiplier applies and the obligation is capped at 35% of the paying parent's adjusted income.

Virginia child support calculator updated for 2025 law change

Virginia's legislature passed SB 805 in 2025, effective July 1, 2025, with a new income schedule and revised shared custody rules. The updated calculator uses the current schedule (covering combined income up to $42,500/month) and applies shared custody treatment when the paying parent has more than 90 days of visitation per year, using a 1.4x multiplier.

California SDI rate updated for 2026

California's State Disability Insurance rate increased from 1.2% to 1.3% for 2026. The California calculator deducts SDI from gross income as part of the net disposable income computation, so this change slightly lowers net income for W-2 employees and, in most cases, modestly reduces the calculated support amount.

Arizona guidelines page expanded

The Arizona how-it-works page was rewritten from a short summary into a full reference covering all eight steps of the Child Support Worksheet, the 2022 guideline changes, parenting time details, when support ends, and nine frequently asked questions. The page now includes structured data for search engines.

Indiana formula corrected — payer was being undercalculated

A user reported getting $18.05/week when the correct answer is $51/week for two parents earning equal incomes. The calculator was giving both parents a parenting time credit and netting them against each other — but only the non-custodial parent (the one with fewer overnights) is supposed to receive the credit. Fixed and verified against Indiana's official child support calculator.

Arizona parenting time credit formula corrected

Arizona's parenting time credit should only apply to the paying parent, calculated as a percentage of the base obligation alone. The original formula incorrectly split the credit between both parents, which underestimated what the paying parent actually owes. Verified against four worked examples in the official Arizona Child Support Guidelines, including the Quinn/Billie and Rory/Finley examples in Appendix X.

Arizona now accounts for children over age 12 and high combined incomes

Arizona adds 10% to each child's support amount when that child is 12 or older (§ III.B.2). You can now specify how many of your children are 12+ and the calculator applies the adjustment automatically. Separately, when combined income exceeds Arizona's $30,000/month schedule cap, the calculator now flags it and explains that courts may order a higher amount based on the children's needs.

Indiana custody input redesigned

Three quick-pick buttons now cover the most common arrangements — no overnights, alternating weekends, and 50/50 — so most people can finish this step in one click. As you adjust, a live card shows both parents' nights side by side and automatically labels the non-custodial parent. No extra input required.

Indiana child support calculator added

Indiana uses a weekly income worksheet rather than the monthly income-shares model used by most states. Built to the 2024 Indiana Child Support Guidelines: weekly gross income, adjusted income, basic obligation from the state schedule, and a parenting time credit based on overnight count. For near-equal custody (181–183 nights), the calculator runs the two-worksheet approach required by Guideline 6.

California child support calculator added

California uses an algebraic formula (Cal. Fam. Code § 4055, updated by SB 343) that works on net disposable income after federal and state taxes, FICA, and deductions — not gross income like most states. The dedicated calculator was built and tested against the state's official DCSS calculator.

"Not yet verified" notice added to all other states

States other than Arizona, California, and Texas now show a notice explaining that while the formula follows published guidelines, the numbers haven't been individually confirmed against official state calculators. This makes it clear which results to treat as estimates and which have been independently checked.

Child Support Math launched

Income-shares calculators for all 50 states and Washington D.C., each with a step-by-step breakdown showing exactly how the number is calculated — not just the final figure. Arizona, California, and Texas were individually verified against official state calculators at launch.