Usually, child support is calculated based on the time schedule of the parents. This schedule refers to which parent takes care of the child on a weekly basis. In the determination of this, it is either parents or a court that will come up with a schedule that the parents and the child will comply with. Most of the time, child support is then calculated on the number the nights spent.
Following this, if one parent gets to have lesser parenting time than the other one, the parent having a lesser amount of parenting time will have to compensate for that time by paying child support to the parent with more parenting time. However, when both parents share an equal amount of parenting time with their children, then the parent who gets to have more income will pay the child support.