Child support guidelines by state

All 50 US states and Washington, D.C. set child support by a published guideline, and each falls into one of a few models. These pages explain how your state calculates it — the formula, the parenting-time thresholds, the income limits, and when an order can change — and link you straight to the official state calculator. They don’t compute a figure themselves, and they aren’t legal advice.

The guideline models

• Income Shares — the most common model. Combines both parents’ incomes, finds the support obligation for that total in a published schedule, and prorates it by each parent’s share.
• Percentage of Income — applies a percentage to the paying parent’s income only (flat or varying by number of children).
• Melson Formula — a needs-based model that reserves each parent’s self-support first, then covers each child’s needs, then splits the surplus (Delaware, Hawaii, and Montana).
• Hybrid — a blend used by Washington, D.C.: it starts from a share of one parent’s income, then adjusts using both parents’ incomes and the children’s needs.