How Missouri Calculates Child Support
Missouri uses the Income Shares model for child support. The governing law is Missouri Revised Statutes Section 452.340, along with the Missouri Supreme Court Rules. Missouri requires that a specific worksheet called Form 14 be completed in every child support proceeding. Form 14 is the official calculation document. Courts must either follow its result or enter written findings explaining why a different amount is appropriate.
Missouri's approach combines both parents' gross monthly incomes to determine the total obligation. Each parent contributes their proportional share. The parent with less parenting time pays their share to the parent with more parenting time.
The Missouri Child Support Formula and Form 14
Missouri's Form 14 calculation follows five steps.
Step one is determining each parent's gross monthly income. Step two is combining both gross incomes. Step three is finding the Presumed Child Support Amount from Missouri's Schedule of Basic Child Support Obligations using the combined income and number of children. Step four is calculating each parent's income share percentage. Step five is applying parenting time adjustments and add-on expenses to produce the final obligation.
A practical example: Parent A earns $5,000 per month. Parent B earns $2,500. Combined income is $7,500. Parent A's income share is 66.7 percent. If Missouri's schedule shows a Presumed Child Support Amount of $1,300 for two children at $7,500 combined income, Parent A's share is $867 per month before adjustments.
Missouri also applies a self-support reserve in cases where a parent's income is very low. When the paying parent's income falls below the self-support threshold, the formula adjusts to prevent the obligation from leaving that parent unable to meet their own basic needs.
What Counts as Income in Missouri
Missouri uses a broad income definition under Section 452.340. Courts include wages, salaries, commissions, bonuses, overtime, 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 can impute income to a parent who is voluntarily unemployed or underemployed based on employment history, education, and the local job market.
Missouri allows each parent to deduct court-ordered child support or maintenance they are currently paying for other relationships from gross income before the formula is applied. This adjustment prevents stacking obligations that make the total unworkable.
Step-by-Step: How to Use This Calculator
Step 1. Get your gross monthly income. Include wages, self-employment income, rental income, and any other regular source. Gross means before taxes and before any deductions.
Step 2. Subtract existing court-ordered obligations. If you are paying child support or maintenance for another relationship, subtract that amount from your gross income before proceeding.
Step 3. Estimate the other parent's gross monthly income after any applicable deductions.
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. Missouri applies a credit when the paying parent has 73 or more overnights per year, approximately 20 percent of the year. Below 73 overnights, no credit applies.
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 Form 14 breakdown. Each line in the results corresponds to a line on Missouri's official Form 14 worksheet.
Parenting Time Adjustments in Missouri
Missouri's 73-overnight threshold is a firm line. Below that mark, no credit applies under the standard formula. At 73 overnights and above, Missouri reduces the paying parent's obligation to reflect the direct costs they bear during their time with the children.
The credit scales with overnights. At 132 or more overnights per year, approximately 36.1 percent of the year, Missouri moves to a more substantial shared parenting calculation. At or near equal parenting time, both parents' obligations are evaluated and the higher earner pays the net difference to the lower earner.
If your parenting time is close to 73 or 132 overnights, counting actual nights rather than estimating is worth doing. Both numbers are firm thresholds that trigger different treatment.
Add-On Expenses in Missouri
Missouri adds healthcare premiums and work-related childcare costs to the Presumed Child Support Amount, allocated proportionally by income share. Extraordinary medical expenses and educational costs may also be addressed through the court order on a case-by-case basis.
Reading Your Results
The results correspond line-by-line with Missouri's Form 14 worksheet. You will see combined gross income, the Presumed Child Support Amount, income shares, the parenting time credit if applicable, add-on costs, and the final monthly obligation.
Missouri courts require Form 14 to be filed with every child support motion. The results from this calculator closely mirror what Form 14 would show. Bring pay stubs and tax returns to verify your gross income before using these results in a legal proceeding.
After You Get Your Estimate
Missouri courts must follow the Form 14 result unless they enter written findings that applying the presumed amount is unjust or inappropriate. Common deviation grounds include extraordinary financial obligations, a child's special needs, significant in-kind contributions, or a parenting arrangement that makes the formula result inequitable.
Modification requires a 20 percent or more change in the calculated obligation, Missouri's statutory threshold for presumptive eligibility. Income changes, parenting time shifts past the 73-overnight or 132-overnight thresholds, and changes in healthcare or childcare costs are all common grounds.
A licensed Missouri family law attorney can help you complete Form 14 correctly and advise on modification options. Many offer a free initial consultation.