In Virginia, child support is determined by a formula. The numbers that are used as inputs to the formula to calculate child support are:
The gross incomes of the parties.
The amount of spousal support paid to one party, if any.
Whether a party supports other children or another child not related to the other party.
The amount of self-employment tax paid, if any.
The number of children the parties have in common
The physical custody schedule, that is the number of days that each parent has the children during the course of a year.
The costs for work related day care.
The costs for the children's health, dental, vision insurance.
The above numbers are entered into the Virginia formula and the amount of child support is determined.
The child support amount is presumptive. The court can deviate from the presumptive child support amount.
There are two formulas: The sole custody formula is used when the non-custodial parent (the parent who has less time with the children) has physical custody of the children for zero to 90 days during a year. The other formula is the shared custody formula. The shared custody formula us used when the non-custodial parent has the children for more than 90 days during the year.
Virginia Code Section 20-108.2 defines a "day" as a period of 24 hours; however, where the parent who has the fewer number of overnight periods during the year has an overnight period with a child, but has physical custody of the shared child for less than 24 hours during such overnight period, there is a presumption that each parent shall be allocated one-half of a day of custody for that period.