Legal Question in Family Law in California

I assume that your question concerns the law, not what should be the law. In CA, the net incomes of the parties are also taken into consideration so that there is no child support only where the time share is equal and the net incomes are equal.

Mr. White is correct regarding the law. If dad earns more, even if custody is 50/50, dad may have to pay mom.

You have gotten correct answers. I just write to elaborate a bit. Child support is calculated by a formula in the Family Code that is so complicated the courts mandate that we use court approved software to do the calculations and produce reports. At the core of it, though, the formula looks at relative incomes and relative time. It determines an amount of disposable income that each parent must contribute to the child. Then the percentage of time the child is with each parent is applied to those amounts. Each parent's contribution is credited to them while they have the child and to the other parent when the other parent has the child. Then a payment is ordered to balance the difference. So if custody is 50/50 and parent one's contribution based on income is determined to be 1000/mo. And parent two's contribution is determined to be 800/mo, P1 is credited 500 plus 400 = 900 on 1000 owed, leaving 100 owed. P2 is credited 500 plus 400 = 900 on 800 owed, leaving 100 due. So the custody and support order would be 50/50 custody with $100/mo child support paid from P1 to P2.