How New Jersey Calculates Child Support

New Jersey uses the Income Shares model to determine child support obligations. This page explains the guidelines, formula, and key factors.

Model Type

Income Shares (N.J. Ct. R. 5:6A, Appendix IX-B/IX-C/IX-D)

New Jersey looks up a basic support amount from the Appendix IX-F schedule by combined weekly net income, then applies the Sole or Shared Parenting Worksheet depending on how much time the children spend with each parent. Net income is estimated from gross using current tax rates, since New Jersey's official withholding tables aren't built into this calculator -- enter an exact net income if you know it.

Sources & Verification

Core formula verified; some gaps disclosed below

Guideline effective 2025-09-01 · last checked against the primary source 2026-08-14

Primary sources

N.J. Ct. R. 5:6A — Child Support Guidelines Appendix IX-A — Considerations in the Use of Child Support Guidelines Appendix IX-B — Use of the Child Support Guidelines (Sole and Shared Parenting worksheet instructions)Appendix IX-C — Sole Parenting Worksheet Appendix IX-D — Shared Parenting Worksheet Appendix IX-F — Schedule of Child Support Awards (rev. eff. 2025-09-01)

What this calculator doesn't yet handle

New Jersey's schedule (Appendix IX-F) runs on net income, and the official gross-to-net conversion is Appendix IX-H's combined withholding tables, which are not transcribed. Net income is instead estimated (shared/nj-tax.ts) from 2026 federal (single-filer, standard deduction) and New Jersey tax rates, FICA/self-employment tax, and NJ SUI/WF/SWF/TDI/FLI payroll contributions. This is the reason New Jersey ships as 'partial' rather than 'verified'. A visitor who knows their exact net income can enter it directly, bypassing the estimator.
The net-income estimator models only the single filing status; head-of-household and married-filing-jointly are not modeled. The federal Child Tax Credit, Earned Income Tax Credit, and other dependent-related credits are not modeled. The 0.9% Additional Medicare Tax above $200,000 is not modeled.
The Shared Parenting Worksheet's household-income safety-net test (Appendix IX-B, Shared Parenting, Line 36) is not implemented. At very low combined income, that test can require recalculating the award under the Sole Parenting Worksheet instead; this calculator does not apply it, so the shared-parenting result shown at low income may be higher than what a court would actually order. It requires the net income of other adults in the primary household, an input this calculator does not collect, and a household-size threshold table (Appendix IX-A ¶14) that could not be fetched during research (njcourts.gov returned HTTP 403 to automated requests — see docs/nj-calculator-spec.md §14).
The Shared Parenting Worksheet requires that the Parent of Alternate Residence provide separate living accommodations for the children — a fact a court decides. This calculator assumes that requirement is met whenever the 104-overnight threshold is met.
The other-dependents adjustment (Appendix IX-B (Sole) Lines 22-24 / (Shared) Lines 30-32, which averages the support obligation with and without deducting other-dependent obligations) is not implemented. This calculator's 'child support actually paid under a prior order' field captures only an existing court-ordered obligation being paid, a simpler and distinct concept.
Split parenting (children divided between the two households) is not implemented.
Imputed income for an unemployed or underemployed parent (Appendix IX-A) is not calculated, only disclosed.
College and post-secondary contribution is not calculated.
Appendix IX-F's 343-row schedule ($180-$3,600/week combined net income, $10 increments) was transcribed from the official PDF using two independent pdftotext extraction algorithms that agree byte-for-byte across all 343 rows, and validated against hand-verified anchor cells and full monotonicity across both income and child count. The schedule's 2-child/1-child award ratio genuinely declines to near 1.0 at the top of the range (two children costing almost the same as one) — confirmed as a real, longstanding feature of this schedule (not a transcription defect) against an independently published mirror of the 2013 revision. See shared/nj-schedule.ts and docs/nj-calculator-spec.md §8 for the full investigation.
Judicial deviations under N.J. Ct. R. 5:6A are not predicted, consistent with every other calculator on this site.