Child support · NH
New Hampshire child support calculator
RSA 458-C:3 applies a percentage of the parents’ combined net income that slides with that income; here is how it is read.
Rules read on official New Hampshire pages on · Checked by Radif Partners · How we calculate
- Model
- Percentage of combined income
- Income counted
- Net income
- Shared parenting
- No fixed formula
- 1 child, $5,000 / $3,000
- $1,020
- a month
New Hampshire takes a percentage of the parents' combined net income and divides the result between them by income. The percentage is not fixed: RSA 458-C:3 lists it at 10 income levels, from 25.6% for one child at $15,000 of annual net income or less to 19% at $125,000 or more, and the Department of Health and Human Services interpolates between the levels. Two parents with $3,000 and $2,000 of net income a month, $60,000 a year together, fall between the $60,000 and $70,000 levels, so the one-child rate is about 22%. The total is $1,100 a month and the parent with 60% of the income owes $660, or $915 for two children. A self-support reserve of $1,729 a month for 2026 limits what a low earner pays, with a $50 minimum order. Orders are rounded to the nearest dollar.
Guideline child support in New Hampshire, per month
$1,020
$12,240 a year
| Combined net income, a year | $96,000 |
| Guideline percentage for 1 child (interpolated, RSA 458-C:3) | 20.4% |
| Total support obligation, a month | $1,632 |
| Paying parent’s share of income | 62.5% |
| Self-support reserve test | applied to the income entered (the statute compares the obligor’s adjusted gross income) |
Estimate under the New Hampshire guideline as published, from the incomes you enter. Deviations, imputed income, other children and the judge's findings can change the order. How this is calculated.
10 income levels and the space between them
Most states print hundreds of rows. New Hampshire's statute prints 10, and each holds four percentages, for one, two, three, and four or more children. Between two levels the percentage moves in a straight line, and DHHS turns that into its yearly Guideline Calculation Table, effective April 1 each year, with a row for every $10 of combined adjusted gross income. The table goes one step further than the statute: it starts from gross income and deducts federal withholding and FICA itself, which is why its net figures can differ by a few cents from a hand calculation. Our calculator takes net income and applies the statutory interpolation directly.
| Annual combined net income | 1 child | 2 children | 3 children | 4 or more |
|---|---|---|---|---|
| $15,000 or less | 25.6% | 35.5% | 42.5% | 45% |
| $25,000 | 25% | 35% | 42% | 44.5% |
| $35,000 | 24% | 33.5% | 40.5% | 43% |
| $50,000 | 23% | 31.5% | 38% | 40.5% |
| $60,000 | 22% | 30.5% | 36.5% | 39% |
| $70,000 | 21.5% | 30% | 36% | 38.5% |
| $80,000 | 21% | 29% | 35% | 37.5% |
| $90,000 | 21% | 28.5% | 34.5% | 37% |
| $100,000 | 20% | 27.5% | 33% | 35.5% |
| $125,000 or more | 19% | 26% | 31% | 33.5% |
The slide is steep at the bottom for large families: with four or more children the rate starts at 45%. At the top, parents with $12,000 and $4,000 a month of net income are well above the last level, so one child is computed at 19%: the paying parent owes $2,280.
The reserve test, and what it does to a modest paycheck
RSA 458-C:3, IV protects the payer in two ways. A payer whose income is below the self-support reserve owes the minimum order, $50 a month, unless voluntarily unemployed. A payer above it may not be pushed below it: the order becomes income minus the reserve, but never less than the minimum. With $2,100 and $1,500 a month and two children, the percentage share is $681; the reserve cuts it to $371. The statute applies the test to the obligor's adjusted gross income; our calculator applies it to the income you enter.
Equal schedules since January 2025
There is no parenting-time formula. Since January 1, 2025, when parents split child care, uninsured medical costs and agreed activities 50/50, two presumptions apply: similar incomes (within 10 percent) and each parent above 40 percent of the time point to a $0 order; similar incomes and each above 35 percent point to a deviation. The court decides, so the calculator shows the guideline amount. Medical support is separate, 4 percent of each parent's gross income. Compare a state that weighs time in its formula on the Maine page.
The New Hampshire guideline this calculator applies
| Rule | New Hampshire |
|---|---|
| Model | Percentage of combined net income (sliding by income level), prorated between parents |
| Income counted | Net income: after income taxes and mandatory deductions, as the state defines it. |
| Official schedule | $15,000 to $125,000 of combined income a month, 10 rows |
| Shared parenting | No overnight formula in the calculator (see the rule below) |
Monthly support for one paying parent, the other parent without income
| Paying parent’s monthly income | 1 child | 2 children | 3 children | 4 children |
|---|---|---|---|---|
| $2,000 | $271 | $271 | $271 | $271 |
| $3,000 | $718 | $1,001 | $1,210 | $1,271 |
| $4,000 | $925 | $1,271 | $1,533 | $1,633 |
| $5,000 | $1,100 | $1,525 | $1,825 | $1,950 |
| $6,000 | $1,284 | $1,788 | $2,148 | $2,298 |
| $8,000 | $1,632 | $2,232 | $2,688 | $2,888 |
| $10,000 | $1,920 | $2,630 | $3,140 | $3,390 |
| $12,500 | $2,375 | $3,250 | $3,875 | $4,188 |
| $15,000 | $2,850 | $3,900 | $4,650 | $5,025 |
| $20,000 | $3,800 | $5,200 | $6,200 | $6,700 |
How the amount is set. Total support obligation = combined net income x the percentage for the number of children (RSA 458-C:3, II(a)); it is divided between the parents in proportion to their incomes (458-C:3, II(b)); obligations are rounded to the nearest whole dollar (458-C:3, II(d)). The percentage table is RSA 458-C:3, I(a); the number of children in the same household is the determining factor (458-C:3, III). source
Income. Gross income = income from any source (wages, salary, commissions, tips, annuities, Social Security, trust income, winnings, interest, dividends, net rental and self-employment income, alimony, business profits, pensions, bonuses, workers' compensation, veterans', unemployment and disability benefits), excluding public assistance programs and occasional/seasonal hourly overtime above 40 hours per week (RSA 458-C:2, IV). Adjusted gross income = gross income minus support paid for others, 50% of self-employment tax, mandatory retirement contributions, state income taxes, and the obligor's actual child care and medical support payments for these children (458-C:2, I). Net income = combined adjusted gross income minus standard deductions published yearly by DHHS for federal income tax and FICA/Medicare (single person, withholding allowance for 2 people) (458-C:2, VI).
Parenting time. No formula adjustment for parenting time. Since January 1, 2025, when parents each pay 50% of child care, uninsured medical and agreed extracurricular costs: substantially similar incomes (gross within 10%) and an approximately equal schedule (each parent more than 40% of parenting time) -> rebuttable presumption of $0 support; substantially similar incomes and a substantially shared schedule (each more than 35%) -> presumption that a deviation is appropriate; with a shared/equal schedule the order should not leave the obligee with higher adjusted income than the obligor (RSA 458-C:2, VIII-c, X-a; 458-C:5, I(h)).
Child care and health care. Not added to the percentage amount; the obligee's allowable child care expenses are deducted from the obligee's adjusted gross income before proration (RSA 458-C:3, II(c)), and the obligor's are deducted from the obligor's adjusted gross income (458-C:2, I(e)). Each parent has a reasonable medical support obligation, presumptively 4% of that parent's gross income (RSA 458-C:3, V). Ongoing extraordinary medical, dental or education expenses are a special circumstance for adjustment (RSA 458-C:5, I(a)).
Low incomes. Self-support reserve = 130% of the federal poverty guideline for one person (RSA 458-C:2, X); DHHS sets it at $1,729.00 per month for 2026 (table effective April 1, 2026). If the obligor's gross income is below the reserve (and not voluntarily unemployed), the order is the $50 minimum; if paying would reduce the obligor's adjusted gross income below the reserve, support = adjusted gross income minus the reserve, but not less than $50 (RSA 458-C:3, IV; 458-C:2, V).
When support ends. Support continues until the child marries, joins the armed services, is emancipated by court order or turns 18; if still a full-time elementary/secondary (or home education) student at 18, until graduation or 2 months after turning 19, whichever is first (RSA 461-A:14, IV, as quoted by NH DHHS). source
The state also runs its own official child support calculator; use it, or the court's worksheet, for a filing.
Worth knowing in New Hampshire
- New Hampshire applies a sliding percentage to the parents' combined net income: from 25.6% (one child) / 45% (four or more) at $15,000 or less of annual net income down to 19% / 33.5% at $125,000 or more (RSA 458-C:3, I(a)). source
- DHHS updates the Child Support Guideline Calculation Table every year, effective April 1; the 2026 table sets the self-support reserve at $1,729.00 per month. source
- Each parent owes a presumptive reasonable medical support obligation of 4% of his or her gross income (RSA 458-C:3, V). source
- Since January 1, 2025, parents with gross incomes within 10% of each other and each with more than 40% of parenting time are presumed to owe $0 support if they split child-related costs 50/50 (RSA 458-C:5, I(h)). source
- Hourly overtime earned occasionally or seasonally beyond 40 hours a week in trades that commonly pay overtime is excluded from gross income (RSA 458-C:2, IV). source