The state has a formula and a chart which helps them determine the amount of support you will receive based on multiple different factors. There are some rare cases where the court will make special exemptions but for the most part, child custody is a carefully calculated and predictable number based on the income of both parents and custody arrangement. For example, if you make less money than your former spouse but you are the primary custody parent you may get a substantial amount of support to help provide for the child.