New Hampshire Child Support Calculator (2025)

Estimate your New Hampshire child support obligation using the Income Shares model under RSA 458-C. New Hampshire considers both parents' adjusted gross income, applies a self-support reserve, and uses a detailed schedule to determine the basic child support obligation.

RSA 458-C Free & Instant 2025 Guidelines
Updated 2025 — New Hampshire RSA 458-C

New Hampshire Child Support Calculator

Uses NH Income Shares model — RSA 458-C with self-support reserve


$
$
$
$


$
$
$
New Hampshire Guideline Child Support
$0 / month
Income Shares — RSA 458-C
Calculation Breakdown
Payment Summary
Monthly Support$0
Annual Support$0
Weekly Equivalent$0
This estimate is for informational purposes only. Consult a New Hampshire family law attorney for accurate calculations.

How New Hampshire Calculates Child Support

New Hampshire uses the Income Shares model under RSA 458-C (Revised Statutes Annotated). This law establishes comprehensive guidelines for calculating child support based on both parents' financial contributions. The NH approach is notable for including a self-support reserve, which ensures that the paying parent retains enough income to meet their own basic needs, preventing the support obligation from pushing them into poverty.

The calculation begins by determining each parent's adjusted gross income. Both adjusted incomes are combined and cross-referenced against the RSA 458-C support schedule to find the basic child support obligation. Each parent's share is proportional to their percentage of the combined income. Additional costs for health insurance, childcare, and extraordinary medical expenses are allocated between the parents in the same proportions.

New Hampshire's guidelines create a rebuttable presumption that the calculated amount is correct. Courts can deviate when the guidelines would produce an unjust or inappropriate result, but must make written findings explaining the deviation. The NH Department of Health and Human Services, Division of Child Support Services, administers enforcement and provides resources for parents navigating the system.

The Self-Support Reserve

One of the most distinctive features of New Hampshire's child support guidelines is the self-support reserve. Under RSA 458-C, the guidelines ensure that after paying child support, the obligor parent retains at least 115% of the federal poverty level for a single individual. This reserve recognizes that a parent who cannot meet their own basic needs will be unable to maintain employment and pay support consistently over time.

If applying the standard guideline calculation would reduce the obligor's income below the self-support reserve, the court adjusts the support amount downward. This does not eliminate the support obligation entirely but ensures a balance between the children's needs and the parent's ability to survive financially. The self-support reserve is adjusted periodically as the federal poverty guidelines are updated.

Income Definitions Under RSA 458-C

New Hampshire defines gross income broadly for child support purposes, including all earned and unearned income:

  • Wages, salaries, tips, and overtime from all employment
  • Commissions, bonuses, and incentive pay
  • Self-employment income after legitimate business deductions
  • Rental and property income
  • Interest, dividends, and capital gains
  • Pensions, retirement, and annuity income
  • Social Security benefits (retirement, disability, survivor)
  • Workers' compensation and disability benefits
  • Unemployment insurance benefits
  • Alimony received from another relationship
  • Trust income and distributions
  • Military pay including all allowances
  • Prizes, awards, and gambling winnings

Allowable deductions from gross income include federal and state income taxes, FICA contributions, mandatory retirement contributions, union dues, alimony paid, and pre-existing child support obligations for other children.

Shared Custody and Parenting Time

New Hampshire addresses shared custody situations where both parents have significant parenting time. When custody is approximately equal (50/50 or near-equal), the court may apply a cross-credit calculation where each parent's obligation is computed separately and the obligations are offset. The parent with the higher income pays the difference to the lower-income parent.

For parenting arrangements that are not 50/50 but still involve significant time with the non-custodial parent, New Hampshire courts may adjust the support amount to reflect the direct costs borne by the non-custodial parent during their parenting time. This adjustment is not automatic and typically requires the parent to demonstrate the additional expenses they incur.

Modification and Enforcement

New Hampshire allows modification when there has been a substantial change in circumstances. Common grounds include changes in income, employment status, custody arrangements, health insurance costs, and the child's needs. Either parent can petition the court for review. The NH Division of Child Support Services also conducts periodic reviews of orders in Title IV-D cases.

Enforcement tools include income withholding, tax refund interception, license suspension (driver's, professional, recreational), contempt proceedings, property liens, bank account seizure, credit reporting, and passport denial. New Hampshire participates in UIFSA for interstate enforcement and the Federal Parent Locator Service.

New Hampshire Child Support and Taxes

New Hampshire has no state income tax on wages and salaries (though it taxes interest and dividends), which simplifies income calculations for many parents. Child support is neither taxable to the recipient nor deductible by the payer under federal law. Standard tax considerations for dependency exemptions, child tax credits, and filing status apply.

New Hampshire RSA 458-C Formula
Parent Share = (Adjusted Income / Combined Income) x Basic Obligation

NH applies a self-support reserve ensuring each parent retains minimum income for basic needs before calculating support

New Hampshire Child Support Schedule

Below is a representative sample of the New Hampshire child support schedule showing basic monthly obligations:

Combined Monthly Income1 Child2 Children3 Children4 Children5 Children
$1,500$273$410$470$508$542
$2,500$400$602$689$746$795
$3,500$497$747$846$920$986
$5,000$625$938$1,060$1,156$1,239
$7,500$817$1,218$1,365$1,497$1,610
$10,000$990$1,468$1,643$1,805$1,943
$15,000$1,285$1,895$2,127$2,341$2,525
$20,000$1,530$2,228$2,510$2,768$2,990

Frequently Asked Questions

How does New Hampshire calculate child support?
NH uses the Income Shares model under RSA 458-C. Both parents adjusted gross incomes are combined, looked up in the schedule, and each parent pays proportionally. A self-support reserve ensures the paying parent retains at least 115% of the federal poverty level.
What is the self-support reserve in NH?
The self-support reserve ensures the obligor retains at least 115% of the federal poverty level for a single person after paying child support. If the guideline amount would push the parent below this threshold, the court reduces the support amount.
What income counts for NH child support?
NH includes all income sources: wages, salaries, bonuses, self-employment, rental, investment, retirement, Social Security, unemployment, workers comp, alimony, and military pay. Deductions include taxes, FICA, mandatory retirement, and pre-existing support.
How does shared custody affect NH child support?
For 50/50 or near-equal custody, NH uses a cross-credit calculation where each parents obligation is computed and offset. The higher-income parent pays the difference to the lower-income parent.
At what age does child support end in NH?
NH child support generally ends at age 18, or at graduation from high school if the child is still attending and under 19. Support may continue for disabled children. College support is not automatically required but can be ordered.
How do I modify child support in NH?
File a motion with the family court showing a substantial change in circumstances. Changes in income, employment, custody, or the childs needs can qualify. Contact the NH Division of Child Support Services for cases administered through the agency.
Can NH courts deviate from guidelines?
Yes, when the guidelines would be unjust or inappropriate. Factors include extraordinary medical expenses, special educational needs, the childs independent income, and other special circumstances. Written findings are required.
Legal Disclaimer: This calculator provides estimates based on New Hampshire guidelines for informational purposes only. It does not constitute legal advice. Consult a qualified New Hampshire family law attorney. Fine Content Limited is not a law firm.