How the calculator works and is tested

All 50 states have a sourced guide. 42 states have a tested calculator that applies the state’s published child-support guideline; the other 8 link to the official worksheet or calculator their courts use.

State guides and state calculators

A state guide explains the legal framework, the income definition, the order of the worksheet and the official resources. A state calculator applies that state’s schedule, percentage or formula to the figures you enter and shows each step. Each guide describes what the calculator covers and which items, such as certain credits or case-specific expenses, are completed on the official form.

Hawaii, Kansas, Massachusetts, Michigan, New Jersey, Oregon, Rhode Island, and Vermont have guides that link to the official tools those states provide. Use the state directory to find the right materials for any state.

What happens to an income entry

1. The entry is converted to the period the state worksheet uses.
2. Income sources are combined for each party, and only the deductions the state permits are applied.
3. The calculator applies the state’s table, percentage or formula to those totals.
4. The result lists each step and the assumptions it used. When an entry requires a branch the calculator does not apply, it stops and leaves a printable input summary instead of an amount.

Whether a deduction is allowed in your case, and whether the court should deviate from the guideline, are decisions for the court.

How the calculator is tested and verified

Every state calculator is held to the numbers the state itself publishes. Before each release, the full automated suite must pass: more than 500 Node.js tests of the calculation engines and pages, plus 28 Python tests of the release and source-monitoring tools.

• Published examples and statutory amounts. Modules reproduce state-published results, including Kentucky’s $60 minimum and $85 reserve amount (KRS 403.212), Nebraska’s $50 minimum and $652 example (§4-221), New Mexico $60 (8.50.108.10), North Carolina $50, Pennsylvania $223 (the Rule 1910.16-2(e)(1)(ii) example), Washington $50 (RCW 26.19.065), Alabama $570 and $50, Arkansas $37 (matching the official AOC calculator), Ohio $80, Virginia $527.34 (§20-108.2(B)) and Iowa $684.75.
• Full schedule checks. All 800 rows of Colorado’s schedule were compared with the signed HB25-1159, and every encoded Minnesota row was compared with §518A.35. Minnesota results match the official state calculator in 24 test cases.
• Boundary tests. Minimum orders, self-support reserves, schedule ceilings, rounding and parenting-time thresholds are tested at and around each cutoff. Cases outside a state’s formula, such as income above a schedule where the court sets the amount, stop without an amount.
• Regression comparison. Releases that change wording or layout are run against the production engine. The most recent comparison returned identical results in 25,256 scenarios.
• Browser testing. Every state workflow is loaded and checked in an automated browser at a 390-pixel mobile width as well as at desktop width.
• Release verification. After each deployment, the engine files served on the live site are compared by SHA-256 hash with the tested files.
• Source monitoring. A daily monitor checks 158 official statutes, court rules, schedules and forms and flags changes for review.

Guideline Calculator is independent software and is not certified or endorsed by any court or agency. The testing above confirms that each calculator matches its state’s published method.

Sources

References are public statutes, court rules, official schedules and agency forms. Each guide records the source’s effective date separately from the date it was last checked.

Calculation corrections, September 17, 2026

• Montana: Worksheets A–E now calculate supported primary, shared and split arrangements with the 2026 allowances, minimum contribution, expenses and travel adjustment. Official worksheets.
• Colorado: corrected the 10% income cap in the reduced-low-income branch, using the signed HB25-1159. All 800 schedule rows were compared with the signed act. Outside-case spousal payments now require review of their tax treatment before deduction.
• Minnesota: added court-ordered parenting time, the more-than-55% presumption, the 2026 self-support reserve and minimum-support treatment. Twenty-four synthetic cases match the official state calculator. Restored the missing $20,000-and-above schedule row and compared every encoded row with §518A.35.
• Schedule ranges: income ranges and additional-child counts outside a published schedule stop calculation instead of reusing a schedule endpoint.
• Georgia and Colorado: cases that need Georgia’s low-income comparison or either state’s parenting-time adjustment stop and direct you to the official worksheet rather than showing an unadjusted amount.

• Texas: reduced percentages now apply below $1,000 in monthly net resources; the standard percentages apply at $1,000. Family Code §154.125.
• Alaska: the ordinary primary-custody minimum and the percentage increase for each child after three are included. Civil Rule 90.3(a)(2) and (c)(3).
• Nevada: all additional children receive the increment in each income tier. NAC 425.140.
• Maine: the table lookup uses the nearest income row and preserves the income proportion until monetary rounding. 19-A §2006.
• Wyoming: income shares retain precision rather than being rounded to whole percentages. §20-2-304.

Spousal support and combined reports

State worksheets include maintenance estimates or advisory ranges where a state publishes a formula, and a needs-and-factors review worksheet where the court decides without one. The 50-state spousal-support report explains the approach in each state.

You can print child and spousal support in one report. The report shows a combined total only when both amounts are calculated, run in the same direction and use a confirmed income order; otherwise the amounts are listed separately. In same-case scenarios, maintenance is applied to child-support income before the child-support calculation. California’s family-support designation is reviewed separately.

New York maintenance

The New York calculator applies the post-divorce maintenance guideline to annual worksheet income up to the statutory cap. Eligibility, duration and maintenance on income above the cap are decided by the court. The next scheduled source review is December 1, 2026, and New York estimates pause until that review is complete.

Use UD-8(2) and UD-8(3) for the official New York worksheets. See our worked basic-support example.

Rounding and comparisons

The calculator rounds at the steps the state worksheet specifies, so monthly and annual figures can differ by a few cents when converted. When comparing with an official tool, use the same inputs, period and schedule version.

Privacy and printing

The financial tools run in your browser and exclude advertising scripts. Support and property worksheets offer optional saving on this device for 30 days after your last edit, with resume and deletion controls. Saving is off until selected; it is not an account or a server backup. Optional analytics on approved public guides and worksheets, and advertising on eligible editorial pages, load only after the relevant consent choice. See privacy and cookie settings.

Report a discrepancy

Send the state, page URL, official source and a hypothetical example to the corrections contact. Explain the expected amount and the worksheet line that supports it. Do not send names, account numbers or confidential case documents.

Updated October 17, 2026. Published by Kestervale LLC. Educational information, not legal advice. Report a correction.