Oregon Child Support Calculator

At $6,000 per month in combined monthly gross adjusted income, Oregon's guidelines produce roughly $852/month for 1 child, $1,225/month for 2 children, $1,435/month for 3 children, $1,603/month for 4 children. These figures come from running Oregon's own guideline formula, but they hold several things constant -- assumes the higher earner has 65% of the combined income shown, no spousal support or non-joint children, and a 265/100 overnight split (below the calculator's default midpoint, so the higher earner is comfortably the paying parent after the parenting-time credit) with no add-ons. Your actual number depends on both parents' incomes, your parenting-time schedule, and add-on costs like childcare and health insurance, so run the calculator for your own case.

Oregon uses the Income Shares model. Oregon looks up a basic support obligation from a scale of combined monthly gross adjusted income and number of children, then applies a continuous parenting-time credit formula to each parent's own overnights rather than a sole/shared custody threshold.

Oregon's guideline runs on combined monthly gross adjusted income. That distinction matters: entering gross income into a formula built on net income (or the reverse) produces a materially wrong figure. Most states count income from essentially any regular source -- wages, self-employment, bonuses, commissions, rental and investment income, and many benefits -- not just salary.

Not necessarily. In Oregon: a logistic formula applied to each parent's own overnights — about 0% near 0 overnights, 50% at an even split, approaching 100% near full-time. Because the guideline also weighs each parent's share of income, a significantly higher earner can still owe support at an even time split.

This calculator's core formula has been verified against the primary source, with any unimplemented rules listed openly rather than hidden. It implements the guideline in effect as of 2026-07-01, and a human last checked it against the primary source on 2026-09-07. Sources: OAR 137-050-0700 to 137-050-0765 — Child Support Guideline Rules; Child Support Guideline Rules with Commentary (PDF, current through July 1, 2026); Updated Obligation Scale B — Table 1 (PDF). It is still an estimate, not a court order -- a judge can order a different amount, and this is not legal advice.

The Oregon guideline this calculator implements took legal effect on 2026-07-01. States revise their guidelines periodically -- federal rules require each state to review its guidelines at least once every four years -- so a figure from an older calculator or article may reflect a superseded rule.

The obligation scale (shared/or-schedule.ts) was extracted programmatically from the appendix PDF's glyph coordinates rather than transcribed from a machine-readable source, because the appendix's multi-line column headers garble both naive text extraction and pdftotext -layout. Validated for internal consistency (contiguous $50 bands, non-decreasing across both axes) and cross-checked against a second, independently-flawed extraction that happened to preserve correct order for its final page — see shared/or-schedule.ts's header for the full method. Not yet checked cell-by-cell against the source PDF. Income is entered as actual gross income only — OAR 137-050-0715's potential/imputed income for a voluntarily unemployed or underemployed parent is not modeled. Adjusted income (OAR 137-050-0720) implements only spousal support paid/received and the non-joint child deduction. Union dues and the parent's own health-insurance-premium deduction are not collected. The non-joint child deduction ((2)(e)) uses a single-parent scale lookup on that parent's own post-spousal-support income, per the rule's own abbreviated method — the rule itself calls this 'only a rough estimate.' Child care costs are not capped against OAR 137-050-0735(3)'s metro-area maximum table, and the disabled-child / under-13 eligibility condition in (1) is not enforced — any entered amount is used as-is. Medical support (OAR 137-050-0750) is simplified to a single children's health-insurance-premium add-on, prorated by income share. The 4%-of-income reasonable-cost cap, the minimum-wage carve-outs, coverage-selection rules, and cash medical support (when neither parent has coverage) are not implemented. Split custody (OAR 137-050-0730(3), each parent primary for a different child) is not implemented — the calculator collects one overnight split applied to all children. The Social Security/Veterans benefits dollar-for-dollar reduction (OAR 137-050-0740) and the minimum order's incarceration/public-benefits/disability-income exceptions ((0755(2)(d)) are not calculated, only the equal-overnights exception is checked. The 'Children Attending School' (18-year-olds still in high school) distinction from ordinary minor children is not modeled — all children in a calculation are treated as minor children. If any of these apply to your case, treat the estimate as a starting point and confirm the figure with an attorney, a mediator, or Oregon's official worksheet.

Yes. The figure produced by Oregon's Income Shares guideline is presumptive, not mandatory: a court can order a different amount when applying the guideline would be unjust or inappropriate for the specific case, and generally must state its reason on the record. Common grounds include extraordinary medical or educational expenses, a child's special needs, or costs the formula does not capture. Oregon's guideline is set out in OAR 137-050-0700 to 137-050-0765 — Child Support Guideline Rules.

You have to file for a modification -- a change in your circumstances does not change what you owe on its own. Oregon, like most states, requires a substantial change in circumstances: a significant involuntary income change, a change in the parenting schedule, or a material change in the child's needs. Until a court or the state child support agency issues a new order, the existing amount stays fully enforceable and arrears keep accruing, and a modification is generally not applied retroactively before the date you filed -- so filing promptly matters. In Oregon, modifications are handled through Oregon DOJ Child Support Program.

Oregon publishes it directly: "Oregon Child Support Guidelines Calculator". This site's calculator is a fast estimate built on the same published guideline, not a replacement for the official form -- a court filing generally requires the state's own worksheet. The link is in the Oregon Resources section on this page.