Overview 

Calculating child support is a complicated process. That is why most attorneys and even self-represented individuals use Family Law Software (familylawsoftware.com) to do so. However, below is an explanation of what is going on behind that software. Because individual circumstances vary and the law changes, you should not rely on this article to calculate child support obligations and should contact a legal professional who can assist you. The following information is for illustrative and informational purposes only. 

Gross Income Calculation

In Colorado, the way child support is calculated is set by statute. To determine how much a parent may have to pay, you must first start with the determination of gross income for each parent. Under Colorado law, § 14-10-115(5)(a)(I), C.R.S. 2020, "gross income" is defined in a way that closely mirrors the United States Internal Revenue Codes definition. That means, that gross income is all income, from whatever source derived, unless it is specifically excluded. Colorado exempts five main sources of income from inclusion in the gross income calculation: (1) child support payments, (2) benefits received from means-tested public assistance programs (such as food stamps), (3) income from additional jobs that result in the employment of the individual more than forty hours per week (or more than what would otherwise be considered full-time employment), (4) social security benefits received by or on behalf of minor children as a result of the death or disability of a stepparent, and (5) earnings or gains on a retirement account (unless or until a parent takes a distribution from the account). In addition, the amount of alimony you include in the calculation depends on whether that income is taxable. If the alimony received is taxable, it is fully included. However, if the alimony is not taxable income, then the amount included as gross income for child support calculation purposes is multiplied by 1.25. Finally, an adjustment for ordinary and necessary expenses is permitted for income from self-employed individuals, and income derived as rent, royalties, and business income. 

In the event that a parent is willfully unemployed or underemployed, child support calculations rely on that parent's potential income instead of their actual income. However, potential income cannot be used for a parent who is physically or mentally incapacitated, a parent who is caring for his or her child under the age of twenty-four months, or a parent who is incarcerated and has been sentenced to one hundred and eight days or more. 

The court will also subtract the amount of child support actually paid in accordance with another child support order (that involves a child from another relationship). If a child from another relationship lives with the parent, that parent is entitled to deduct a limited amount for basic support obligations. If a child from another relationship does not live with the parent, the court is supposed to deduct the "documented" money payments actually paid by the parent for the support of the child limited to basic support obligations. 

Basic Child Support Obligation

Once you have the amount of gross income for each parent, you add them together. Then, you take the total and find the basic child support obligation. When the obligor parent (the parent who pays support) has income of at least $1,500 per month you will look up the amount of the child support obligation in a chart. For example, if a set of parents had a combined gross income of $48,000 per year and had two children between them, there would be a basic child support obligation of $1,053 per month. However, very high income individuals (those with a combined gross income of over $360,000 per year) may have the basic child support obligation increased above the maximum set forth in the chart. It should be noted that the basic child support obligation is multiplied by 1.5 in the case of shared physical care. Further, certain other adjustments may increase the obligation. 

Division of Basic Child Support Obligation between Parents

Once you have found the basic child support obligation, you must allocate it between the parents in proportion to their adjusted gross income. For example, lets suppose the one of the members of the couple with a combined gross income of $48,000 per year made $2,200 per month while the other made $1,800 per month. That would mean the one making $2,200 per month earned 55% of the total income while the individual making $1,800 per month earned 45% of the total income. You would then multiple the basic child support obligation by each parent's percentage of the total income to get that parent's child support obligation. Thus, the parent making $2,200 per month would have an obligation of $579.15 per month ($1,053 X 55% = $579.15), and the other parent would have an obligation of $473.85 per month ($1,053 X 45% = $473.85). However, these numbers still need to be adjusted for the amount of time each parent spends with the child. 

When there is shared physical care, the adjustment is as follows: In order to adjust for the amount of time the child is with each parent, each parent will multiply the amount of his or her obligation by the amount of time the other parent spends with the child. For example, if the parent with the income of $2,200 has the child during weekdays and ever other weekend, he or she will multiply his obligation by 14.29% (2/14 days). This would result in an obligation of $82.76. Meanwhile the parent with income of $1,800 per month would multiply his or her obligation by 85.71%, which would result in an obligation of $406.14. The parent owing the greater amount of child support (here the parent making $1,800 per month) would then owe the difference between the obligations. Thus, the parent making $1,800 per month would owe the parent earning $2,200 per month $323.38 each month ($406.14 - $82.76 = $323.38). 

 When there is split physical care, the adjustment is as follows: Each parent will multiple their basic child support obligation by the percentage of children residing with the other parent. Then the parent with the higher obligation shall pay the other parent the difference between the obligations.