Child Support Calculator

🔒 Everything is calculated in your browser. Nothing you enter is sent to or stored on any server. Your approximate location (state) is read from your network connection only to match you with the right state’s guidelines. Only your state choice and a license token (no personal or case data) are kept on your device, so the app opens in the right state and runs offline for up to a week between check-ins. Anonymous, aggregate usage counts (which state’s calculator is opened — never your numbers) help us know where to improve.

1 Parenting arrangement

Primary residence — the children primarily reside with one parent for approximately 2/3 of the time (Box 2) Shared — the parents share financial responsibility and parenting time approximately equally (Box 1) Split — more than one child, and each parent provides a primary residence for at least one child (Box 3)

For primary residence, Parent A is the parent the children primarily live with.

2 Income & costs

Amounts entered as The guidelines calculate weekly; other frequencies are converted for you.

A child receives a Social Security dependency benefit (parent's retirement or disability)

Based on which parent's record?

Benefit sent to Parent A ($/wk) Benefit sent to Parent B ($/wk)

Child care costs paid for children covered by this order

Per child, weekly. The guidelines consider up to $430/week per child of combined child care cost.

3 Alimony (optional)

Alimony may also be ordered — run the Cavanagh comparison

Where both alimony and child support are contemplated, Cavanagh v. Cavanagh, 490 Mass. 398 (2022) requires comparing an alimony-first calculation against a child-support-first calculation, including tax consequences. The M.G.L. c. 208 § 53(b) guideline range (30–35% of the gross income difference) was calibrated when alimony was tax-deductible; for post-2018 orders alimony is tax-neutral, and a lower percentage is commonly applied. Actual alimony is need-based and discretionary.

Alimony percentage of income difference Children claimed for tax purposes by Parent A filing status Parent B filing status

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Android (Chrome)

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1 Parenting arrangement

2 Income & costs

3 Alimony (optional)

Cavanagh comparison

Presumptive weekly order