Massachusetts Child Support Calculator
Estimate monthly child support under Massachusetts's official guideline model. Updated for 2026.
Last reviewed July 2026 · Free · Nothing you enter is stored
Estimate monthly child support under Massachusetts's official guideline model. Updated for 2026.
Last reviewed July 2026 · Free · Nothing you enter is stored
Massachusetts uses the income shares model: both parents' incomes are combined, a basic support obligation is determined from the state's guideline schedule, and each parent is responsible for their proportional share. The parent without primary custody typically pays their share to the other household.
Governing law: Mass. Trial Court Child Support Guidelines (eff. Dec. 1, 2025) — New quadrennial guidelines effective Dec 1, 2025; formula applies to combined available gross income with a $400,000 cap before discretion.
Massachusetts publishes an official calculator that applies the full guideline schedule: official Massachusetts child support calculator. Use ours for a quick, private estimate and theirs when you need the exact worksheet figure.
Massachusetts uses the income shares model: both parents' incomes are combined, a basic support obligation is determined from the state's guideline schedule, and each parent is responsible for their proportional share. The parent without primary custody typically pays their share to the other household. The guideline is set by Mass. Trial Court Child Support Guidelines (eff. Dec. 1, 2025).
No — this is a guideline estimate. Courts start from the guideline amount but can deviate for factors like extraordinary medical costs, special needs, other support obligations, or agreements between parents. For an official figure, use the state’s own calculator linked on this page or consult a family law attorney.
In most states, including under most guideline models, substantial parenting time (often above roughly 20–30% of overnights) reduces the paying parent's obligation. Our calculator applies a simplified parenting-time adjustment; Massachusetts's courts apply their own specific rules, so treat shared-custody results as rough estimates.
Generally all income: wages, self-employment, bonuses, commissions, and often investment income. Massachusetts's guideline uses gross (pre-tax) income figures. Courts may also impute income to a parent who is voluntarily unemployed or underemployed.