The child support guidelines are mandated by federal and state law and "place a primary emphasis on the net incomes and earning capacities of the parties." The guidelines must be reviewed at least every four years. The amount of child support is determined in accordance with the Pennsylvania Support Guidelines. In computing a support amount, the court must consider the parties' earning capacities as well as their actual earnings and other financial resources. Child support is based on the parties' respective net incomes. Net income is determined by subtracting only specified deductions from a party's gross income. Permissible deductions are federal, state and local income taxes, social security deductions, non-voluntary retirement contributions, union dues and alimony paid to the other party.

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Deviations from the guideline figure are permitted only on the basis of specific factors. The court must specify in writing the guideline amount and set forth findings of fact and reasons justifying any deviation. In determining whether a deviation from the guideline amount is appropriate, the trier of fact must consider the unusual needs and fixed obligations, other support obligations, other household income, the ages of the children, the assets of the parties, uninsured medical expenses, the standard of living of the parties and other relevant factors.