New Hampshire Child Support Calculator

It depends on both parents’ monthly income before taxes, the number of children, and, when each parent has more than 35% of the time, the parenting schedule. If you earn $1,000 a week, the other parent earns $3,000 a month, and your one child spends 4 nights a month with you, you would pay about $748 a month, or $1,043 a month for two children.

To build the table, we convert weekly pay to monthly pay (× 52 ÷ 12) and assume neither parent has deductions like required retirement or support paid for other children. In the first rows, the paying parent earns less than, or barely more than, the $1,729 New Hampshire leaves them to live on, so the order is the $50 minimum. New Hampshire’s guideline table, which lists support for both parents together, is in the DHHS 2026 Child Support Guidelines.

New Hampshire uses an income shares formula. It adds both parents’ incomes, subtracts a standard amount for federal income tax, Social Security, and Medicare, and applies a percentage for the number of children. Each parent then pays a share that matches their share of the income.

The rules are in RSA 458-C:3, with the income terms in RSA 458-C:2:

1. Find each parent’s gross income from all sources. Public assistance, like SSI, FANF, and SNAP, doesn’t count, and neither does occasional or seasonal hourly overtime.
2. Subtract the allowed deductions to get adjusted gross income: court-ordered support paid for others, half of self-employment tax, required retirement, state income tax, and the paying parent’s child care for work and the children’s health coverage.
3. Look up the table amount for the combined adjusted gross income and number of children. The table already subtracts a standard amount for federal tax, Social Security, and Medicare, then applies the percentage set by law.
4. Split it by income share. A parent with 60% of the combined income owes 60%.
5. Check the low-income limit ($1,729 a month the paying parent keeps) and the $50 minimum.
6. Consider the parenting schedule if each parent has more than 35% of the time.

Example

One parent earns $4,000 a month and the other $2,000, with no deductions, so their combined adjusted gross income is $6,000. The table amount for one child is $1,094. The higher earner has two thirds of the income, so with the child living mostly with the other parent, they pay about $729 a month.

It can, once each parent has more than 35% of the parenting time (about 128 nights a year). From there, support usually shouldn’t leave the parent receiving it with more income after taxes than the paying parent. If each parent has more than 40% of the time and their incomes are within 10% of each other, the court starts from $0 support. With one child and gross pay of $5,000 and $4,000 a month, the higher earner pays $825 a month at 35% or less and about $402 with more than 35% each ($402 at equal time).

New Hampshire measures parenting time as each parent’s share of the yearly schedule. These rules apply when the parents each pay half of child care for work, uninsured medical bills, and agreed activities:

• More than 40% each and gross incomes within 10%: the court starts from $0 support. With equal time, one child, and gross pay of $4,000 and $3,700, the estimate is $0.
• More than 35% each and incomes within 10%: the court starts from the view that the guideline amount should be changed.
• More than 35% each and incomes further apart: the judge decides whether the guideline amount fits, mainly by asking whether the lower earner can raise the children in a similar way.
• More than 35% each, any incomes: support usually shouldn’t leave the parent receiving it with more income after federal tax, Social Security, and Medicare than the parent paying it. The calculator above limits support to half the gap between the two parents’ after-tax incomes. So if the parent with less time also earns less, they pay nothing: with gross pay of $4,000 and $5,000 and 40% of the time, the lower earner’s estimate is $0.

The calculator above assumes these conditions hold. Exactly 40% doesn’t count as more than 40%. These rules may not apply when there is abuse, a child with serious health needs, a long distance between homes, or an unpredictable work schedule. See RSA 458-C:5, I(h) and the definitions in RSA 458-C:2.

Child care a parent needs for work changes the incomes the formula uses. The paying parent’s child care costs come out of their income before the table, and the receiving parent’s child care costs lower that parent’s share of the support.

Child care counts when a parent needs it for work, including education or training the job requires. With shared parenting, splitting child care 50/50 is one of the conditions for the shared-time rules. See RSA 458-C:2, I and RSA 458-C:3, II(c).

Each parent is expected to put up to 4% of their gross income toward the children’s health care. If a parent can add the children to nearby private insurance for that amount or less, the court orders it. If not, the parent pays that amount in cash toward medical costs.

• Nearby coverage: the children’s primary care doctor is within 50 miles or one hour of their main home. The cost counted is what it costs to add the children, under RSA 461-A:14, IX.
• Combining: the court can combine both parents’ 4% amounts to pay for coverage.
• Uninsured bills: every order must say who pays medical costs insurance doesn’t cover.

The 4% presumption is in RSA 458-C:3, V.

If the children live with you and you get FANF (New Hampshire’s cash assistance), you have to help the state get child support from the other parent, for example by naming them and going to paternity tests and court dates. The state keeps the support it collects while you get assistance. Food stamps (SNAP) don’t require this.

• Financial Assistance to Needy Families (FANF): not helping without a good reason cuts the cash grant for most families, under the Family Assistance Manual.
• Support kept by the state: none of it is added to your FANF check. New Hampshire keeps it to repay the assistance and sends support to you once assistance ends.
• Food stamps (SNAP): USDA lists New Hampshire as a state that doesn’t require you to help with child support to get SNAP.
• A paying parent on SSI or cash assistance: DHHS doesn’t collect support while they get it, and an order the state is collecting on doesn’t build up back child support, under RSA 461-A:14, XIII.

If helping could put you or your children in danger, you can ask to be excused (New Hampshire calls this “good cause”). The New Hampshire child support guide has more on benefits and child support.

In 2026, the paying parent gets to keep $1,729 a month to live on (called the self-support reserve). Support can’t take more than what they earn above $1,729. The order is still at least $50 a month, though a judge can order less.

• Paying parent just above $1,729: with gross pay of $1,829 and the other parent at $4,000, support is $100, the amount above $1,729.
• Paying parent under $1,729: at $1,700, the order is the $50 minimum.
• Earning less by choice: a judge can base support on what a parent could earn if they choose not to work or to work less, unless a physical or mental condition keeps them from working. Time in jail or prison never counts as a choice.

See RSA 458-C:3, IV for the reserve and RSA 458-C:2 for the minimum order and earning ability. The $1,729 is 130% of the federal poverty guideline for one person, changes each year, and is printed on the 2026 table.

No. The percentages level off at $125,000 a year of combined income after taxes, from 19% for one child to 33.5% for four or more, and keep applying above that. A judge can lower support that would far exceed what the children reasonably need.

The percentages are 19% for one child, 26% for two, 31% for three, and 33.5% for four or more at that level, under RSA 458-C:3, I. The printed 2026 table ends at $31,119 combined a month; the DHHS calculator goes higher. The high-income rule is in RSA 458-C:5, I(b).

Yes. A judge can order a different amount for one of the reasons the law lists. The judge has to state, in writing or in the court record, why the guideline amount would be unfair or wrong for the family.

Reasons the law lists include large ongoing medical, dental, or education costs, a parent’s very high or very low income, stepchildren or other children, a parent’s costs of parenting time, the sale of the family home, tax effects, the parenting schedule, and college costs. Parents who agree on a different amount still need the judge to state why it fits.

See RSA 458-C:4 and RSA 458-C:5.

Either parent can ask for a new calculation 3 years after the last order without showing any change, or sooner after a big change in circumstances. Keep following the current order until it changes. A new amount can’t start before the other parent gets notice of the request.

• Through DHHS: if your case is with the Bureau of Child Support Services, ask it to review your order. Its Modification Kit lists the forms.
• Through the court: file a Petition to Change Court Order (NHJB-2062-F) in the Circuit Court Family Division.

The rules are in RSA 458-C:7. The New Hampshire child support guide walks through each step.

Yes. New Hampshire DHHS publishes the Child Support Guidelines Calculator, which follows the Child Support Guidelines Worksheet and the yearly guideline table.

Open the Child Support Guidelines Calculator or download the worksheet and table from the DHHS guidelines page. The parent asking for support files a completed worksheet at every hearing, under RSA 458-C:3-a.