In most cases, child support is calculated pursuant to the Utah Uniform Child Support Guidelines. The guidelines take into account the relative incomes of the parents and the amount of time each parent has custody. You can calculate your child support obligation with a Sole Custody Child Support Worksheet or Joint Custody Child Support Worksheet. It is extremely difficult to deviate from the established child support guidelines. You would have to establish that using the guidelines for your particular case would be unjust, inappropriate or contrary to the best interests of your child.
After child support has been determined by the court and a final support order has been entered, child support can be modified only upon a change in circumstances. Three years after a support order has been entered, you may move the court to adjust child support if your current obligation would be 10% more or 10% less than your previously ordered obligation. If less than three years has lapsed since entry of a prior order, you can move the court to modify that order only if your income has changed by 30% or more or you can establish some other substantial change in circumstances.