New Hampshire Child Support Calculator

Estimate New Hampshire child support for 2026 using the Income Shares guideline model under RSA 458-C. Enter both parents' incomes and the parenting-time split to see what you may owe or receive.

New Hampshire follows the Income Shares model under RSA 458-C. The court combines both parents' monthly net incomes, looks up the basic support obligation on the state's guideline schedule for that income level and number of children, then prorates the obligation between the parents according to each parent's percentage share of the combined income.

New Hampshire uses a shared-care parenting-time formula, and the prose explains that a parenting-time adjustment applies when a parent's overnights exceed 30 percent of the year. Below that threshold, the standard prorated obligation generally stands. Above it, the formula recognizes that the parent with significant overnights is already covering more day-to-day costs. The on-page calculator gives an estimate only, so confirm any shared-parenting adjustment on the official worksheet or with a licensed attorney.

New Hampshire treats the cost of the child's health insurance as an add-on under RSA 458-C. The premium attributable to the children is factored in and then shared between the parents in proportion to their share of combined income, just like the basic support obligation. The parent who actually pays the premium typically receives credit for it. Because exact handling depends on your numbers, treat the calculator result as an estimate and verify the split on the official guideline worksheet.

Work-related child care, such as daycare needed so a parent can hold a job, is an allowed adjustment under New Hampshire's guidelines. These costs are added to the support figure and divided between the parents according to each parent's percentage of the combined net income. The parent who pays the provider is generally credited for that parent's portion. The estimator approximates this, so confirm the actual child care split on the official New Hampshire worksheet.

A New Hampshire judge starts with the guideline number under RSA 458-C, which is presumed correct. The court may deviate when applying the guideline would be unjust or inappropriate given the specific facts, such as extraordinary expenses, a child's special needs, or other circumstances the statute recognizes. The parent asking for a different amount carries the burden of showing why a deviation is warranted, and the judge must put written reasons on the record. The calculator cannot predict a deviation.

Frequently asked questions

How is child support calculated in New Hampshire?

New Hampshire uses the Income Shares model under RSA 458-C. The court first combines both parents' monthly net incomes, then looks up the basic support obligation on the state's guideline schedule for that combined income level and the number of children. That obligation is prorated between the parents based on each parent's percentage share of the combined income, so the higher earner generally carries a larger portion. Add-ons like health insurance and work-related child care are layered on and split the same way. The calculator on this page gives an estimate, but the official New Hampshire guideline worksheet and a licensed attorney control the final number.

Is there an official New Hampshire child support worksheet I should use?

Yes. New Hampshire has an official guideline worksheet tied to RSA 458-C, and it is the controlling form the family division of the circuit court relies on to set support. The state's family division child support resources at courts.nh.gov walk you through combining net incomes, applying the guideline schedule, and adding allowed costs. The estimate you get on this page is a helpful preview, but it is not legal advice and does not replace that worksheet. Complete the official form, or have a licensed attorney or the New Hampshire Division of Child Support Services review your numbers, before you rely on any figure in court.

How does New Hampshire treat overtime, bonuses, and self-employment income?

New Hampshire defines income broadly under RSA 458-C. The guideline counts income from nearly any source, including wages, salaries, commissions, self-employment, royalties, bonuses, severance, pensions, retirement, dividends, interest, rental income, Social Security, workers' compensation, and unemployment benefits. That means a steady pattern of overtime or recurring bonuses can be included, and self-employment income is examined after legitimate business expenses. Because the state works from net income, allowable deductions matter to the final figure. This calculator can only approximate that, so confirm exactly what counts as income on the official New Hampshire worksheet or with a licensed attorney.

What if one parent is unemployed or underemployed in New Hampshire?

If a parent has no income or earns less than they could, a New Hampshire court can look past the paycheck and consider that parent's true earning capacity rather than letting support drop to nothing. Under the RSA 458-C framework, the guideline is built around each parent's share of combined income, so a parent who is voluntarily not working can still be expected to contribute. The judge weighs work history, skills, and job opportunities. Because imputing income is fact-specific and discretionary, the estimate here cannot account for it. Speak with a licensed attorney or the New Hampshire Division of Child Support Services about how earning capacity might apply to your case.

Does 50/50 or shared parenting time change child support in New Hampshire?

It can. New Hampshire applies a shared-care parenting-time formula, and a parenting-time adjustment kicks in once a parent's overnights exceed 30 percent of the year. When custody is closer to equal, the formula recognizes that both parents are already covering substantial direct costs, which can reduce the amount that changes hands compared with a standard order. Even in a near 50/50 split, support is rarely zero because the parents' incomes usually differ and the higher earner still owes a share. This calculator estimates the effect, but the official New Hampshire worksheet and a licensed attorney determine the actual shared-parenting result.

How are health insurance, daycare, and uninsured medical costs divided in New Hampshire?

Under RSA 458-C, New Hampshire adds certain expenses on top of the basic guideline obligation and splits them in proportion to each parent's share of combined net income. The child's health insurance premium and work-related child care are recognized adjustments, and the parent who actually pays gets credit for that parent's portion. Uninsured and out-of-pocket medical costs are commonly divided by the same income-share percentages. Because the exact treatment depends on your figures, the estimate here is only a starting point. Confirm how each add-on is allocated on the official New Hampshire guideline worksheet or with a licensed attorney.

When does child support end in New Hampshire, and how do I modify an order?

In New Hampshire, child support generally ends at age 18 or upon the child's graduation from high school, whichever is later, but not past age 19. Continuing support for a disabled adult child can be available. To change an existing order, you file a petition in the family division of the circuit court or request a review through the New Hampshire Division of Child Support Services. Modification is supported by a 20 percent variance between the current order and a fresh guideline calculation, or by any substantial change in circumstances. The Division of Child Support Services also enforces orders through income withholding, tax intercept, license suspension, liens, credit reporting, and contempt referrals.