Colorado law provides for a mathematical formula for the calculation of child support. Both parties’ incomes along with certain expenses paid on behalf of the child/children are entered into the calculation. Factors such as the amount of overnights each parent has can, in some cases, change the presumptive amount of support to be paid. In general, Colorado law provides that child support may be modified upon a showing that a continuing and substantial change of circumstances has occurred. The change must affect the child support to result in a change 10% or greater from the current amount in order for the Court to review the matter. Certain situations allow for a deviation from the presumptive child support number and provisions for payment of medical insurance and/or daycare may be grounds for a modification.