New Hampshire Child Support Calculator

New Hampshire uses the income shares model under RSA 458-C:3, combining both parents' adjusted gross incomes and applying a guideline percentage — 25% for one child, 33% for two, 40% for three, and 45% for four or more. The total obligation is then divided proportionally based on each parent's share of combined income. The state's guideline table covers combined monthly incomes up to $226,009.

Under RSA 458-C:2, gross income includes wages, salaries, bonuses, commissions, pensions, Social Security benefits, and rental income. Allowable deductions include federal and state taxes, mandatory retirement contributions, and pre-existing child support obligations. If a parent is voluntarily unemployed or underemployed, the court may impute income based on their earning capacity.

As of January 1, 2025, New Hampshire recognizes specific parenting time thresholds under RSA 458-C. An approximately equal schedule — where each parent has more than 40% of parenting time — creates a presumption of no child support order. A substantially shared schedule exceeds 35% for each parent. Parents with substantially similar incomes, defined as a gap of 10% or less, may also see adjustments.

Under RSA 458-C:7, either parent can request a review of their child support order every three years without proving a change in circumstances. If seeking modification before three years, the requesting parent must demonstrate a substantial change such as job loss, significant income fluctuation, or a change in custody arrangements. The court recalculates using the current guideline table.

New Hampshire child support covers basic needs including housing, food, clothing, and transportation. Under RSA 458-C:2, the presumptive medical support obligation is 4% of each parent's gross income. Additional expenses such as childcare costs, extraordinary medical or dental expenses, and education costs for special needs may be added under the special circumstances provisions of RSA 458-C:5.

New Hampshire sets a minimum child support order of $50 per month under RSA 458-C:2, V, even if the obligor is unemployed — unless the court finds a lesser amount appropriate. The self-support reserve is 130% of the federal poverty guideline for a single person. The guideline table covers combined monthly incomes up to $226,009; amounts above that require consultation with the Bureau of Child Support Services.

Under RSA 461-A, child support in New Hampshire continues until the child reaches age 18, marries, joins the armed services, or is legally emancipated. If the child is still a full-time student at a secondary or elementary school at age 18, support extends until graduation or two months after the child turns 19, whichever comes first. New Hampshire does not require support through college.

New Hampshire enforces child support through income withholding orders that employers must implement within 14 days, with wage garnishment up to 65% of net pay for parents with arrears under 15 USC 1673(b). Additional enforcement includes driver's license suspension under RSA 263:56-a, professional license suspension, and passport denial when arrears exceed 12 weeks. The court may also initiate contempt proceedings under RSA 458:17, which can result in fines or incarceration.