How Massachusetts calculates child support
- Each parent’s available income is weekly gross income minus other support they pay, health care premiums and dental/vision insurance.
- The combined available income, up to $8,654 a week ($450,000 a year), sets the support for one child from Table A; Table B adjusts it for more children and Table C for children 18 or older.
- The parent the children live with less pays the other parent’s share in proportion to income. Shared and split arrangements are figured for each parent and offset.
- Child care paid so a parent can work is shared in proportion to income, up to $430 per child per week.
- A payor with available income of $391 a week or less pays a minimum amount from the shaded area of the chart.
What the calculator asks
- How many children is the support for?
- How do the children split their time?
- How many of the children are 18 or older?
- How many of the children live mainly with you?
- How many of the children who live with you are 18 or older?
- How many of the children who live with the other parent are 18 or older?
- Your gross income per week
- Child support or alimony you pay each week under another order
- Health insurance premium you pay each week
- Dental or vision insurance you pay each week for these children
- The other parent’s gross income per week
- Child support or alimony the other parent pays under another order
- Health insurance premium the other parent pays each week
- Dental or vision insurance the other parent pays each week for these children
- Child care you pay each week so you can work
- Child care the other parent pays each week so they can work
- How many of the children are in that paid child care?
- Does any child receive a Social Security dependency benefit because of a parent’s retirement or disability?
It never asks for names, Social Security numbers or account numbers, and your answers are not saved.
What the estimate leaves out
- Social Security dependency benefits for the children
- Support on combined income above $8,654 a week, which the court decides
- Uninsured medical and dental costs, which the court divides separately
- Deviations the court may make (Guidelines § IV)
When a situation is outside what the calculator covers, it says so and points you to the official worksheet instead of guessing.
Official sources
- Massachusetts Child Support Guidelines (effective Dec. 1, 2025)
- Child Support Guidelines Worksheet, CJD 304 (12/01/2025)
- 2025 Child Support Guidelines Chart
Child Support Guidelines Worksheet (CJD 304) →
Ready to estimate? The calculator shows each worksheet line so you can check it against the official form.
Open the Massachusetts calculator →An estimate from the published guideline formula, not a prediction of a court order. The official court worksheet and the court’s decision control. General information, not legal advice. LawCat is not a law firm.