Idaho Child Support Calculator

How Idaho Calculates Child Support

Idaho calculates child support to ensure your children receive the same financial support as if you lived together. Governed by I.R.F.L.P. 120, the state adds both your incomes, finds a total support amount from a schedule, and then divides it between you based on your percentage of the combined income.

Shared Custody & Parenting Time Adjustments

In Idaho, shared physical custody significantly impacts child support when each parent has the children for at least 92 overnights per year (25% of the time). Under I.R.F.L.P. 120, the court uses a special formula that increases the basic obligation by 50% and then credits each parent for the time they have the children, which typically reduces the final support amount.

Calculate Your Support

✓ Verified for 2026 Guidelines • Reviewed October 2026 by Harmoney

Idaho Child Support Guidelines at a Glance

Guideline Model Income Shares Model
Governing Legal Authority Idaho Rules of Family Law Procedure 120 (I.R.F.L.P. 120)
Shared Custody Threshold 92 Overnights (25% time)
Age Support Ends Age 18 (or 19 if still in High School)
Modification Standard Substantial and Material Change in Circumstances

Frequently Asked Questions about ID Child Support


At what age does child support end in ID?

Child support in Idaho ends when a child turns 18, or if they are still attending high school, it continues until they graduate or turn 19, whichever occurs first. This is mandated by Idaho Code § 32-706, which defines the legal duration of a parent's duty to support their child.

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

If a parent is unemployed or underemployed, Idaho courts may impute potential income to them based on their work history, qualifications, and local job market opportunities. According to I.R.F.L.P. 120, income will be imputed unless the parent is physically or mentally unable to work, ensuring both parents contribute fairly.

How do I modify a child support order in ID?

To modify a child support order in Idaho, you must prove a substantial and material change in circumstances has occurred since the last order was entered. This standard is established in Idaho Code § 32-709 and does not rely on a specific percentage change, but rather on significant events like a job loss or major change in parenting time.

Does ID child support cover college expenses?

No, Idaho law does not require parents to pay for college expenses as part of a child support order, as the obligation legally ends at age 18 or 19. However, parents may voluntarily agree to contribute to post-secondary education costs and make that agreement part of a legally binding marital settlement agreement.

How does ID handle health insurance and childcare costs?

Health insurance premiums and work-related childcare costs are typically added to the basic child support obligation and divided between the parents in proportion to their incomes. As outlined in I.R.F.L.P. 120, these necessary expenses are shared to ensure the child's needs are met beyond the basic support amount.