How to Calculate Child Support Payments in New Hampshire

To estimate the amount of support under New Hampshire's current child support guidelines, you can use the official New Hampshire Child Support Calculator. The online calculator will create the worksheet that you’ll submit with your request for child support (more on that below). Here’s what you’ll need to get started.

How to Use the New Hampshire Child Support Calculator

Before using the calculator, you’ll need to gather some basic financial information for both parents, including:

• income
• state income taxes and self-employment taxes (if either parent is self-employed)
• mandatory retirement contributions (required by your employer)
• the cost of adding the children to health insurance coverage
• expenses for work-related child care, and
• court-ordered child support payments for other children (from different relationships).

You’ll also need to know which parent will have primary physical custody of your children (the custodial parent, called the “obligee” on the worksheet). Although the calculator shows each parent’s support obligation, the noncustodial parent (the “obligor”) will pay child support to the custodial parent. New Hampshire assumes that the custodial parent meets that obligation by paying directly for the children’s day-to-day expenses.

Unlike in many other states, New Hampshire’s child support calculation doesn’t have built-in adjustments or separate calculations when parents have joint physical custody or when the noncustodial parent has extensive parenting time. Instead, those custody arrangements might be a reason for deviations from the guideline calculation (more on that below).

Once you fill in your information, the online calculator will automatically fill in the totals. You can then print and save the worksheet. If you have questions about completing the worksheet, the calculator has a link to the PDF version of the worksheet, which includes full instructions—including a description of what’s included in gross income.

When Child Support May Be Different Than the Guideline Calculation

New Hampshire presumes that the amount calculated under the guidelines is appropriate, but you may argue that a different amount would be better in your situation. Whether you and the child's other parent have agreed on a support amount that departs from the guideline or a judge decides for you, the judge will have to find that using the amount calculated under the guidelines would be unjust or inappropriate in light of the special circumstances in your case.

Although the parenting schedule is one of the examples of special circumstances listed in the guidelines, the fact that the parents share equal or nearly equal physical custody (known as “residential responsibility” in New Hampshire law) won't be a reason on its own for the judge to allow a deviation in the guideline calculation of child support. When a parent is requesting a deviation based on the parenting schedule, the judge may consider whether:

• the parents have agreed to a specific allocation of child-related expenses (other than fixed costs, like housing),
• the obligor has demonstrated that the other parent’s fixed child-related costs will be reduced because of the shared custody arrangement, and
• the lower-earning parent will be able to meet the costs of caring for the child with a similar standard of living as the child will have when living with the higher-earning parent.

(N.H. Rev. Stat. §§ 458-C:4(II), 458-C:5 (2024).

Learn more about how child support works in New Hampshire, including the other special circumstances that may justify a deviation from the guidelines.

How to Apply for Child Support in New Hampshire

Typically, you'll apply for child support as part of the process of filing for divorce in New Hampshire. You'll include your completed child support worksheet along with the other divorce papers.

Outside of the divorce context, you may get help with requesting support by applying for child support services from New Hampshire’s Bureau of Child Support Services (BCSS). If needed, the DCSS may also help with establishing the child's legal paternity and locating an absent parent.

How to Collect Child Support in New Hampshire

Most child support in New Hampshire is paid through income withholding. That way, the support payments are automatically taken out of the noncustodial parent’s paychecks. When income withholding isn’t possible or appropriate (such as when a parent is self-employed), New Hampshire’s BCSS offers several ways of making child support payments

The BCSS can also help you if you aren’t receiving support payments on time (or at all). Depending on how much the other parent owes, the agency has several ways of enforcing child support, including:

• reporting the debt to credit bureaus
• intercepting income tax refunds
• seizing money from bank accounts,
• placing liens on property (so the delinquent parent can’t sell it or borrow money before paying off the debt)
• suspending the parent’s driver’s or other licenses, and
• requesting a hearing to have the delinquent parent found in contempt of court, which can lead to fines and even jail time.

How to Change the Amount of Child Support

Either parent may request a modification in the amount of child support in New Hampshire. However, a judge won’t modify support unless:

• it’s been three years since the date of your most recent order, or
• there’s been a substantial change in circumstances that makes the existing amount of support unfair.

(N.H. Rev. Stat. § 458-C:7(I)(a) (2024).)

You may request a review of your current child support order from the New Hampshire BCSS to see if you might qualify for a modification. (You’ll need to apply for services first if you don’t already have a case with the agency.) But the BCSS itself can’t modify your order—only the court may do that.

Any modified child support order will be based on a calculation under the guidelines, using your current financial circumstances, unless you can show that there are unusual circumstances justifying a deviation (as discussed above).