Guideline Child Support

California uses an algebraic formula known as the Statewide Uniform Guideline for calculating child support. The Guideline is contained in Family Code Section 4055 which expresses the formula as:

CS = K[HN – (H%)(TN)]

CS = child support amount.
K = amount of both parents’ income to be allocated for child support.
HN = high earner’s net monthly disposable income.
H% = approximate percentage of time that the high earner has or will have primary physical responsibility for the children compared to the other parent.  
TN = total net monthly disposable income of both parties.”

Net Monthly Disposable Income

One of the most significant factors in calculating child support is net monthly disposable income. To establish net monthly disposable income the court must first determine the gross income of each parent, then subtract allowable deductions.

Gross Income

Gross income is broadly defined as income from whatever source derived, except income that is legally exempt from the child support calculation. (See Family Code Section 4058(a)). At a minimum gross income includes:

• Wages, commissions, salaries, and bonuses
• Interest, royalties, dividends
• Rents,
• Pensions, annuities, trust income,
• workers’ compensation benefits, unemployment insurance benefits, disability insurance benefits, social security benefits
• spousal support actually received from a person not a party to the child support proceeding
• Business income, self employment earnings

Deductions

After determining gross income the court must subtract allowable deductions to yield net monthly disposable income. Unfortunately for the high-earning parent, allowable deductions are rather limited and include:

• Federal and state income taxes that are actually payable; the amount may differ from taxes withheld.
• FICA contributions
• Mandatory union dues and retirement benefits
• Health insurance premiums for the parent and any child which the parent has an obligation to support
• State disability premiums
• Child and spousal support actually being paid pursuant to a court order. Support being paid without a court order may be deducted under certain circumstances up to the amount established by the State Uniform Guideline.
• Job related expenses as permitted by the court
• Hardship deduction due to extraordinary health expenses or uninsured catastrophic loss.

Time-Share with Children

H% represents the percentage of time the high-earning parent will have primary physical responsibility for the child relative the low-earning parent. The court will typically impute time share to the parent with custody when the child is in school or day care, so long as the custodial parent has physical responsibility for the child at that time. Examples of physical responsibility for the child during school or daycare include transportation to and from school, emergency contact during school hours, and participation in school activities and functions.