How South Carolina Calculates Child Support
South Carolina uses the Income Shares model for child support. The governing law is South Carolina Code Section 63-17-470, along with the South Carolina Child Support Guidelines. South Carolina uses gross income as the basis for its calculation and combines both parents' incomes to determine the total obligation. Each parent then contributes their proportional share.
South Carolina applies a specific parenting time credit called the extraordinary visitation credit when the non-custodial parent has significant overnight time. The 109-overnight threshold is the key dividing line in South Carolina.
The South Carolina Child Support Formula
South Carolina's calculation follows four steps.
Step one is determining each parent's monthly gross income. Step two is combining both gross incomes to produce the combined monthly gross income. Step three is finding the Basic Child Support Obligation in South Carolina'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 practical example: Parent A earns $5,000 per month. Parent B earns $2,500 per month. Combined income is $7,500. Parent A's income share is 66.7 percent. If South Carolina's schedule shows a Basic Child Support Obligation of $1,300 for two children at $7,500 combined income, Parent A's base obligation is $867 per month before the extraordinary visitation credit and add-ons.
What Counts as Income in South Carolina
South Carolina uses a broad income definition. Courts include wages, salaries, commissions, bonuses, overtime, self-employment income, rental income, pension and retirement distributions, Social Security benefits, SSDI payments, veterans' benefits, unemployment compensation, workers' compensation, and income from any other regular source.
Courts can impute income to a parent who is voluntarily unemployed or underemployed based on work history, education, and local job market conditions.
South Carolina allows deductions from gross income before combining incomes: court-ordered child support currently being paid for children from other relationships. This deduction reduces the adjusted gross income used in the proportional share calculation.
South Carolina excludes needs-based public assistance from the income calculation.
Step-by-Step: How to Use This Calculator
Step 1. Get your gross monthly income. Include all income sources before taxes and deductions.
Step 2. Subtract existing court-ordered child support payments you are making for children from other relationships.
Step 3. Estimate the other parent's adjusted gross monthly income using the same method.
Step 4. Enter the number of children covered by this order.
Step 5. Count your actual overnights per year. South Carolina applies the extraordinary visitation credit when the non-custodial parent has 109 or more overnights per year, approximately 30 percent of the year. If you are near that threshold, count carefully. Divide overnights by 365 to enter your percentage.
Step 6. Add healthcare costs. Enter the monthly premium for the children's health insurance.
Step 7. Add childcare costs. Enter monthly work-related childcare expenses.
Step 8. Review the full breakdown before accepting the result.
Parenting Time Adjustments in South Carolina
South Carolina calls its parenting time adjustment the extraordinary visitation credit. The credit applies when the non-custodial parent has 109 or more overnights per year, approximately 30 percent of the year.
Below 109 overnights, no credit applies under the standard formula. At 109 overnights and above, South Carolina reduces the paying parent's obligation to reflect the direct costs they bear during their substantial parenting time. The credit scales as overnights increase toward equal parenting time.
At near-equal parenting time, both parents' obligations are evaluated and the higher earner pays the net difference. South Carolina courts recognize that both parents are spending directly on the children when parenting time is substantial.
The 109-overnight threshold is a firm line. Moving from 108 to 109 overnights triggers the extraordinary visitation credit. If your parenting time is close to that mark, counting actual overnights is worth doing.
Add-On Expenses in South Carolina
South Carolina adds healthcare premiums and work-related childcare costs to the base obligation, allocated proportionally by income share. Courts may also address extraordinary medical expenses and educational costs on a case-by-case basis.
Reading Your Results
The results display shows each parent's adjusted gross income, combined gross income, the Basic Child Support Obligation from South Carolina's schedule, income share percentages, the extraordinary visitation credit if applicable, add-on costs, and the final monthly obligation.
If your overnight count is close to 109, the extraordinary visitation credit line in the results will tell you whether the credit was applied. A difference of even one or two overnights near that threshold can change whether the credit applies at all.
After You Get Your Estimate
South Carolina courts follow the Section 63-17-470 guidelines in all standard cases. Deviation is allowed when the guideline amount would be unjust or inappropriate. Courts document deviations with specific written findings.
Modification in South Carolina requires a substantial change in circumstances. A 20 percent or more change in the calculated obligation is a commonly applied threshold. Income changes, a shift in overnights past the 109-night extraordinary visitation threshold, and changes in the children's needs are the most common grounds.
A licensed South Carolina family law attorney can review your calculation and advise on the extraordinary visitation credit or modifications. Many offer a free initial consultation.