First, convert to a monthly figure
The California formula runs on monthly income, so the first step is getting there. At $2,000 a week, you multiply by 52 weeks and divide by 12 months, which works out to $8,667 a month. Everything below assumes that figure.
What actually drives the number
There’s no flat percentage. California uses the FC section 4055 formula, and the result moves with several inputs:
- Your income and the other parent’s income
- Timeshare, meaning the share of time the kids spend with each of you
- The number of children
- Your tax filing status and deductions
- Other deductions such as health insurance or a 401(k)
Change any one of these and the number changes.
Some example scenarios
These assume one child, married-filing-separately status, and the standard deduction. First, with the other parent earning nothing:
| Your timeshare | Guideline CS | You pay |
|---|---|---|
| 10% (every other weekend) | ~$1,600/mo | You pay other parent |
| 20% | ~$1,550/mo | You pay other parent |
| 30% | ~$1,470/mo | You pay other parent |
| 50% (equal custody) | ~$1,210/mo | You pay other parent |
Now if the other parent brings in $4,000 a month of their own:
| Your timeshare | Guideline CS |
|---|---|
| 20% | ~$1,360/mo |
| 50% | ~$600/mo |
What the tables tell you
Two patterns stand out. The more time the kids spend with you, the lower your obligation, since you’re already covering their costs directly during that time. And the other parent’s income matters a great deal: the more they earn, the smaller your payment. Push both factors at once, equal incomes and 50/50 custody, and support lands near zero.
Keep in mind these are estimates built on standard deductions and MFS filing. Your real number shifts with your actual deductions and filing status. To pin it down, open this $8,667/month example and drag the timeshare slider to match your own custody split.