Child Support Estimator

Estimating child support can be stressful and confusing, especially when navigating a separation or divorce. This child support calculator uses the income shares model — the most common method in the United States, used by approximately 40 states — to provide a general estimate of monthly payment obligations. While every state has its own specific formula and guidelines, the income shares approach provides a reasonable starting framework for understanding how support payments are typically calculated.

Step 1: Enter Each Parent's Gross Monthly Income

Start by entering the gross monthly income (before taxes and deductions) for both parents. Parent 1 is designated as the custodial parent — the parent with whom the children primarily reside. Parent 2 is the non-custodial parent. Include all sources of income: wages, salary, self-employment income, bonuses, commissions, and any other regular earnings. If income is irregular, use a monthly average based on the past year.

Step 2: Select the Number of Children

Choose the number of children covered by the support order, from 1 to 6. The base obligation percentage increases with more children: one child uses approximately 20% of combined income, while six children uses about 43%. These percentages are based on national economic research into the cost of raising children at various income levels.

Step 3: Choose the Parenting Time Split

Select the parenting time arrangement that best matches your situation. The split represents the percentage of overnights spent with the custodial parent. A 70/30 split means the custodial parent has the children about 70% of the time. When the non-custodial parent has more than 25% of overnights, a parenting time credit reduces their obligation — reflecting that they are already covering expenses during their time with the children.

Step 4: Add Health Insurance and Childcare Costs

Enter the monthly cost of health insurance for the children and any childcare expenses such as daycare or after-school care. These add-on costs are divided proportionally between parents based on their income shares. Many states treat these as separate line items that are added to the base child support obligation rather than included in the percentage calculation.

Step 5: Review the Estimate

After clicking "Estimate Child Support," you will see the estimated monthly payment, who pays whom, a complete breakdown of the calculation steps, and the annual total. The breakdown shows the base obligation, each parent's income share, the parenting time adjustment, and any add-on expenses. Use this estimate as a starting point for discussions with your attorney or mediator — actual court-ordered amounts may differ based on your state's specific guidelines, deductions, and judicial discretion.

Understanding the Formula

The income shares model works as follows: Combined Income = Parent 1 + Parent 2. Base Obligation = Combined Income x Rate (based on number of children). Each parent's share = their income / combined income x base obligation. If the non-custodial parent has significant parenting time, their obligation is reduced proportionally. Health insurance and childcare costs are then added based on each parent's income share percentage. All calculations run privately in your browser and no data is stored or shared.