How Idaho Calculates Child Support
Idaho uses the Income Shares model for child support. The governing law is Idaho Code Section 32-706, along with the Idaho Child Support Guidelines adopted by the Supreme Court of Idaho. Idaho's guidelines use gross monthly income as the basis for calculation, the same starting point used by most Income Shares states.
The Income Shares model in Idaho is built on the principle that children should receive the same proportion of parental income they would have received if the household had stayed together. Both parents' gross monthly incomes are combined, the total child-rearing cost is determined from Idaho's Basic Support Schedule, and each parent contributes their proportional share.
The Idaho Child Support Formula
Idaho's calculation follows four steps.
Step one is determining each parent's monthly gross income. Step two is combining both incomes to produce the combined gross monthly income. Step three is finding the Basic Support Obligation in Idaho's schedule using the combined income and number of children. Step four is calculating each parent's income share percentage and applying it to the obligation.
A straightforward example: Parent A earns $4,000 per month. Parent B earns $2,500 per month. Combined income is $6,500. Parent A's income share is 61.5 percent. Parent B's income share is 38.5 percent. If Idaho's schedule shows a Basic Support Obligation of $1,100 for two children at $6,500 combined income, Parent A's base obligation is $677 per month.
The parent with less parenting time pays their share to the parent with more parenting time. Healthcare and childcare are added on top of the base obligation.
Idaho also has a specific provision for split custody situations, when each parent has primary custody of at least one child from this relationship. In those cases, separate obligations are calculated in both directions and then offset against each other.
What Counts as Income in Idaho
Idaho uses a broad income definition. Courts include wages, salaries, commissions, bonuses, overtime, tips, self-employment income, rental income, pension and retirement distributions, Social Security benefits, SSDI payments, unemployment compensation, workers' compensation, and income from any other regular source.
Courts in Idaho can impute income to a parent who is voluntarily unemployed or underemployed based on their earning capacity. The court considers work history, education, job market conditions, and the reasonableness of the parent's employment choices. A parent who chooses lower-paying work when higher-paying work is available at their skill level can expect the court to use the higher figure.
Idaho excludes child support received for children from other relationships and certain public assistance benefits from the income calculation.
Step-by-Step: How to Use This Calculator
Step 1. Get your gross monthly income. Include all income sources. Gross means before taxes and before any deductions. If your income varies seasonally or by commission, average the last 12 months.
Step 2. Subtract any existing court-ordered child support payments you are currently paying for children from another relationship. Idaho adjusts for prior orders before entering the formula.
Step 3. Estimate the other parent's gross monthly income using the same method.
Step 4. Enter the number of children covered by this order.
Step 5. Enter your parenting time percentage. Count actual overnights per year and divide by 365. Standard visitation, every other weekend and some holidays, is roughly 14 to 20 percent. Equal time is 50 percent.
Step 6. Add healthcare costs. Enter the monthly cost of the children's health insurance premium only, not the portion covering you as the employee.
Step 7. Add childcare costs. Enter monthly work-related childcare expenses that allow either parent to work.
Step 8. Review the full breakdown before accepting the result.
Parenting Time Adjustments in Idaho
Idaho applies a parenting time adjustment when the non-custodial parent has significant parenting time. The adjustment reflects that a parent who spends more time with their children is also spending more directly on them, food, clothing, activities, and daily costs during their parenting time.
Standard every-other-weekend visitation in Idaho runs roughly 14 to 20 percent of overnights and generally does not trigger a meaningful credit. As parenting time increases past that level, Idaho courts may apply a reduction. At 50/50 parenting time, Idaho calculates both parents' obligations and offsets them. The higher-earning parent typically pays a net amount to the lower-earning parent even at equal time, unless incomes are close to equal.
Courts in Idaho have discretion to deviate from the guideline when the parenting schedule is unusual or when the standard formula produces an unfair result given the actual time each parent spends with the children.
Add-On Expenses in Idaho
Idaho adds healthcare premiums and work-related childcare costs to the base obligation, allocated proportionally by income share. Extraordinary unreimbursed medical expenses can also be addressed through the court order and split proportionally between the parents.
Reading Your Results
The results display shows combined gross income, the Basic Support Obligation from Idaho's schedule, each parent's income share percentage, the parenting time adjustment if applicable, add-on costs, and the final monthly obligation.
If your income is variable, seasonal work, self-employment, or commission-based pay, confirm that your gross monthly income reflects a true 12-month average. A single high or low month can significantly distort the result.
After You Get Your Estimate
Idaho courts follow the guidelines as the default in all cases. Deviation is permitted when the guideline amount would be unjust or inappropriate given the specific circumstances. Courts weigh the child's actual needs, both parents' financial resources, the parenting arrangement, and any special factors.
Modification in Idaho requires a material change in circumstances. A 15 percent or more change in the calculated obligation is the common benchmark, though the statute focuses on whether the change is substantial and continuing. Income changes, custody changes, and changes in the children's needs are the most common grounds for filing.
A licensed Idaho family law attorney can review your calculation and advise on whether your circumstances support a deviation or modification.