New Hampshire Child Support Calculator

How is Child Support Calculated in New Hampshire?

New Hampshire calculates child support based on the idea that your child should receive the same portion of parental income they would have if you lived together. Governed by NH RSA 458-C, the court combines both your and the other parent's gross incomes to find a total support amount, then divides it based on your percentage share of that combined income.

NH Shared Custody and Child Support Adjustments

In New Hampshire, shared parenting time can significantly adjust the child support amount. Under NH RSA 458-C, if each parent has the child for at least 146 overnights per year, a special calculation is used which increases the total support obligation by 50% and then allocates it between you based on income and time with the child. This formula recognizes the duplicated costs common in shared parenting arrangements.

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✓ Verified for 2026 Guidelines • Reviewed October 2026 by Harmoney

New Hampshire Child Support Guidelines at a Glance

Guideline Model Income Shares Model
Governing Legal Authority NH RSA 458-C
Shared Custody Threshold 146 Overnights
Age Support Ends Age 18 (or completion of high school, whichever is later)
Modification Standard Substantial Change in Circumstances

Frequently Asked Questions about NH Child Support


At what age does child support end in NH?

Child support in New Hampshire generally ends when a child turns 18 or graduates from high school, whichever occurs later, as established by NH RSA 461-A:14. A court may order support to continue past this point if the child is disabled or under other specific circumstances found to be equitable.

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

If a parent is voluntarily unemployed or underemployed, New Hampshire courts will impute income to them based on their earning capacity, considering their recent work history, skills, and local job opportunities. This means the calculation will be based on what the parent could be earning, not their actual low income, to ensure the child's needs are met per NH RSA 458-C.

How do I modify a child support order in NH?

You can request a modification of a child support order in New Hampshire upon showing a substantial change in circumstances that makes the original order unfair or improper. Pursuant to NH RSA 458-C:7, either parent can also request a review of the order every three years without needing to prove a substantial change.

Does NH child support cover college expenses?

New Hampshire courts can order a parent to contribute to college expenses, but it is not mandatory and is decided on a case-by-case basis. Under NH RSA 461-A:14, a court may order support for post-secondary education if it finds it is equitable after considering factors like the parents' finances and the child's academic aptitude.

How does NH handle health insurance and childcare costs?

Health insurance premiums and reasonable work-related childcare costs are typically added to the basic child support obligation and divided between the parents in proportion to their respective incomes. This is outlined in NH RSA 458-C:3 to ensure these necessary expenses are shared equitably on top of the base support amount.