Oregon Child Support Calculator

How Oregon's Child Support Formula Works

Oregon determines child support using an 'Income Shares Model', which estimates the amount you and the other parent would have spent on your children if you were still together. Governed by Oregon Revised Statutes § 25.275, this total obligation is then divided between you based on your individual shares of the combined parental income.

Shared Custody & Parenting Time Adjustments

In Oregon, shared physical custody significantly alters the child support calculation if a parent has care of the child for at least 92 overnights per year (25% of the time). When this threshold is met, Oregon's rules (OAR 137-050-0750) trigger a 'parenting time credit' calculation that increases the basic support obligation by 50% ('gross-up') and then allocates that new amount based on each parent's percentage of overnights.

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✓ Verified for 2026 Guidelines • Reviewed October 2026 by Harmoney

Oregon Child Support Guidelines at a Glance

Guideline Model Income Shares Model
Governing Legal Authority ORS § 25.275 / OAR 137-050-0700 et seq.
Shared Custody Threshold 92 Overnights (25% Time)
Age Support Ends Age 18 (or 21 if a 'Child Attending School')
Modification Standard Substantial Change in Circumstances

Common Questions About Oregon Child Support


At what age does child support end in OR?

Child support in Oregon generally ends when a child turns 18, but it can be ordered to continue until age 21 if the child is a 'child attending school' as defined by ORS 107.108. This typically includes children enrolled at least half-time in high school, college, or a vocational program.

How is child support calculated if one parent is unemployed in OR?

If a parent is unemployed or underemployed in Oregon, a court can calculate child support by imputing a potential income based on what that parent is capable of earning. This determination, governed by ORS 25.280, considers the parent's work history, skills, education, and local job market conditions, and is often based on a full-time, minimum-wage job at a minimum.

How do I modify a child support order in OR?

To modify a child support order in Oregon, you must demonstrate a 'substantial change in economic circumstances' that is significant and was not anticipated when the last order was entered. This standard, outlined in ORS 25.287, could include a major change in income, parenting time, or the needs of the child.

Does OR child support cover college expenses?

Yes, Oregon courts can order a parent to contribute to college or other post-secondary education expenses for a child until they reach age 21. Under ORS 107.108, a court may require support for a 'child attending school,' provided the child maintains at least a half-time course load and makes satisfactory academic progress.

How does OR handle health insurance and childcare costs?

Health insurance premiums and reasonable, work-related childcare costs are treated as add-on expenses to the basic child support obligation in Oregon. These costs are prorated between the parents based on their respective shares of their combined income, and the non-paying parent's share is added to their support obligation.